diff --git a/integration-tests/delete-scripts/__snapshots__/delete-scripts.test.ts.snap b/integration-tests/delete-scripts/__snapshots__/delete-scripts.test.ts.snap
index 734a41f3..f0ac31dc 100644
--- a/integration-tests/delete-scripts/__snapshots__/delete-scripts.test.ts.snap
+++ b/integration-tests/delete-scripts/__snapshots__/delete-scripts.test.ts.snap
@@ -2,6 +2,14 @@
 
 exports[`Test delete-scripts: a patch file got produced 1`] = `
 "SNAPSHOT: a patch file got produced
+# generated by patch-package 0.0.0 on 1980-01-01 00:00:00
+#
+# command:
+#   npx patch-package left-pad
+#
+# declared package:
+#   left-pad: file:/mocked/path/to/left-pad-1.3.0.tgz#5b8a3a7765dfe001261dde915589e782f8c94d1e
+#
 diff --git a/node_modules/left-pad/index.js b/node_modules/left-pad/index.js
 index e90aec3..f2b8b0a 100644
 --- a/node_modules/left-pad/index.js
diff --git a/integration-tests/file-mode-changes/__snapshots__/file-mode-changes.test.ts.snap b/integration-tests/file-mode-changes/__snapshots__/file-mode-changes.test.ts.snap
index 9bffcbf4..2c491ecd 100644
--- a/integration-tests/file-mode-changes/__snapshots__/file-mode-changes.test.ts.snap
+++ b/integration-tests/file-mode-changes/__snapshots__/file-mode-changes.test.ts.snap
@@ -2,6 +2,14 @@
 
 exports[`Test file-mode-changes: the patch file 1`] = `
 "SNAPSHOT: the patch file
+# generated by patch-package 0.0.0 on 1980-01-01 00:00:00
+#
+# command:
+#   npx patch-package prettier
+#
+# declared package:
+#   prettier: file:/mocked/path/to/prettier-1.16.0.tgz#104dd25f5ee3d0c9d0a6ce4bb40ced8481d51219
+#
 diff --git a/node_modules/prettier/bin-prettier.js b/node_modules/prettier/bin-prettier.js
 old mode 100755
 new mode 100644
diff --git a/integration-tests/happy-path-npm/__snapshots__/happy-path-npm.test.ts.snap b/integration-tests/happy-path-npm/__snapshots__/happy-path-npm.test.ts.snap
index ee54e635..e29cac23 100644
--- a/integration-tests/happy-path-npm/__snapshots__/happy-path-npm.test.ts.snap
+++ b/integration-tests/happy-path-npm/__snapshots__/happy-path-npm.test.ts.snap
@@ -17,6 +17,14 @@ END SNAPSHOT"
 
 exports[`Test happy-path-npm: the patch looks like this 1`] = `
 "SNAPSHOT: the patch looks like this
+# generated by patch-package 0.0.0 on 1980-01-01 00:00:00
+#
+# command:
+#   npx patch-package left-pad
+#
+# declared package:
+#   left-pad: file:/mocked/path/to/left-pad-1.1.3.tgz
+#
 diff --git a/node_modules/left-pad/index.js b/node_modules/left-pad/index.js
 index 26f73ff..d4cc4af 100644
 --- a/node_modules/left-pad/index.js
diff --git a/integration-tests/happy-path-yarn/__snapshots__/happy-path-yarn.test.ts.snap b/integration-tests/happy-path-yarn/__snapshots__/happy-path-yarn.test.ts.snap
index 0b22e347..39c683ba 100644
--- a/integration-tests/happy-path-yarn/__snapshots__/happy-path-yarn.test.ts.snap
+++ b/integration-tests/happy-path-yarn/__snapshots__/happy-path-yarn.test.ts.snap
@@ -17,6 +17,14 @@ END SNAPSHOT"
 
 exports[`Test happy-path-yarn: the patch looks like this 1`] = `
 "SNAPSHOT: the patch looks like this
+# generated by patch-package 0.0.0 on 1980-01-01 00:00:00
+#
+# command:
+#   npx patch-package left-pad
+#
+# declared package:
+#   left-pad: file:/mocked/path/to/left-pad-1.1.3.tgz#612f61c033f3a9e08e939f1caebeea41b6f3199a
+#
 diff --git a/node_modules/left-pad/index.js b/node_modules/left-pad/index.js
 index 26f73ff..b083802 100644
 --- a/node_modules/left-pad/index.js
diff --git a/integration-tests/ignore-whitespace/__snapshots__/ignore-whitespace.test.ts.snap b/integration-tests/ignore-whitespace/__snapshots__/ignore-whitespace.test.ts.snap
index e5b5c464..ef3f0866 100644
--- a/integration-tests/ignore-whitespace/__snapshots__/ignore-whitespace.test.ts.snap
+++ b/integration-tests/ignore-whitespace/__snapshots__/ignore-whitespace.test.ts.snap
@@ -9,6 +9,14 @@ END SNAPSHOT"
 
 exports[`Test ignore-whitespace: line a changed 1`] = `
 "SNAPSHOT: line a changed
+# generated by patch-package 0.0.0 on 1980-01-01 00:00:00
+#
+# command:
+#   npx patch-package alphabet
+#
+# declared package:
+#   alphabet: file:/mocked/path/to/alphabet
+#
 diff --git a/node_modules/alphabet/index.js b/node_modules/alphabet/index.js
 index 7811d3b..454414b 100644
 --- a/node_modules/alphabet/index.js
diff --git a/integration-tests/ignores-scripts-when-making-patch/__snapshots__/ignores-scripts-when-making-patch.test.ts.snap b/integration-tests/ignores-scripts-when-making-patch/__snapshots__/ignores-scripts-when-making-patch.test.ts.snap
index 1c31fe46..0fd38fe7 100644
--- a/integration-tests/ignores-scripts-when-making-patch/__snapshots__/ignores-scripts-when-making-patch.test.ts.snap
+++ b/integration-tests/ignores-scripts-when-making-patch/__snapshots__/ignores-scripts-when-making-patch.test.ts.snap
@@ -2,6 +2,14 @@
 
 exports[`Test ignores-scripts-when-making-patch: a patch file got produced 1`] = `
 "SNAPSHOT: a patch file got produced
+# generated by patch-package 0.0.0 on 1980-01-01 00:00:00
+#
+# command:
+#   npx patch-package naughty-package
+#
+# declared package:
+#   naughty-package: file:/mocked/path/to/naughty-package
+#
 diff --git a/node_modules/naughty-package/postinstall.sh b/node_modules/naughty-package/postinstall.sh
 index 3784520..c4af29c 100755
 --- a/node_modules/naughty-package/postinstall.sh
diff --git a/integration-tests/include-exclude-paths/__snapshots__/include-exclude-paths.test.ts.snap b/integration-tests/include-exclude-paths/__snapshots__/include-exclude-paths.test.ts.snap
index d9aeefa1..8f18bb45 100644
--- a/integration-tests/include-exclude-paths/__snapshots__/include-exclude-paths.test.ts.snap
+++ b/integration-tests/include-exclude-paths/__snapshots__/include-exclude-paths.test.ts.snap
@@ -2,6 +2,14 @@
 
 exports[`Test include-exclude-paths: exclude all but flip 1`] = `
 "SNAPSHOT: exclude all but flip
+# generated by patch-package 0.0.0 on 1980-01-01 00:00:00
+#
+# command:
+#   npx patch-package lodash --exclude '^(?!.*flip)'
+#
+# declared package:
+#   lodash: file:/mocked/path/to/lodash-4.17.4.tgz#78203a4d1c328ae1d86dca6460e369b57f4055ae
+#
 diff --git a/node_modules/lodash/flip.js b/node_modules/lodash/flip.js
 index c28dd78..584b377 100644
 --- a/node_modules/lodash/flip.js
@@ -17,6 +25,14 @@ END SNAPSHOT"
 
 exports[`Test include-exclude-paths: modified package.json 1`] = `
 "SNAPSHOT: modified package.json
+# generated by patch-package 0.0.0 on 1980-01-01 00:00:00
+#
+# command:
+#   npx patch-package lodash --exclude '^$'
+#
+# declared package:
+#   lodash: file:/mocked/path/to/lodash-4.17.4.tgz#78203a4d1c328ae1d86dca6460e369b57f4055ae
+#
 diff --git a/node_modules/lodash/package.json b/node_modules/lodash/package.json
 index 028960d..7d346f3 100644
 --- a/node_modules/lodash/package.json
@@ -35,6 +51,14 @@ END SNAPSHOT"
 
 exports[`Test include-exclude-paths: no base files 1`] = `
 "SNAPSHOT: no base files
+# generated by patch-package 0.0.0 on 1980-01-01 00:00:00
+#
+# command:
+#   npx patch-package lodash --exclude base
+#
+# declared package:
+#   lodash: file:/mocked/path/to/lodash-4.17.4.tgz#78203a4d1c328ae1d86dca6460e369b57f4055ae
+#
 diff --git a/node_modules/lodash/flip.js b/node_modules/lodash/flip.js
 index c28dd78..584b377 100644
 --- a/node_modules/lodash/flip.js
@@ -64,6 +88,14 @@ END SNAPSHOT"
 
 exports[`Test include-exclude-paths: only __.js being deleted 1`] = `
 "SNAPSHOT: only __.js being deleted
+# generated by patch-package 0.0.0 on 1980-01-01 00:00:00
+#
+# command:
+#   npx patch-package lodash --include __
+#
+# declared package:
+#   lodash: file:/mocked/path/to/lodash-4.17.4.tgz#78203a4d1c328ae1d86dca6460e369b57f4055ae
+#
 diff --git a/node_modules/lodash/fp/__.js b/node_modules/lodash/fp/__.js
 deleted file mode 100644
 index 4af98de..0000000
@@ -76,6 +108,14 @@ END SNAPSHOT"
 
 exports[`Test include-exclude-paths: only base files, no clone files 1`] = `
 "SNAPSHOT: only base files, no clone files
+# generated by patch-package 0.0.0 on 1980-01-01 00:00:00
+#
+# command:
+#   npx patch-package lodash --include base --exclude clone
+#
+# declared package:
+#   lodash: file:/mocked/path/to/lodash-4.17.4.tgz#78203a4d1c328ae1d86dca6460e369b57f4055ae
+#
 diff --git a/node_modules/lodash/_baseClamp.js b/node_modules/lodash/_baseClamp.js
 index a1c5692..c52e38e 100644
 --- a/node_modules/lodash/_baseClamp.js
diff --git a/integration-tests/lerna-canary/__snapshots__/lerna-canary.test.ts.snap b/integration-tests/lerna-canary/__snapshots__/lerna-canary.test.ts.snap
index 1dfdf267..56a74428 100644
--- a/integration-tests/lerna-canary/__snapshots__/lerna-canary.test.ts.snap
+++ b/integration-tests/lerna-canary/__snapshots__/lerna-canary.test.ts.snap
@@ -25,6 +25,14 @@ END SNAPSHOT"
 
 exports[`Test lerna-canary: the patch looks like this 1`] = `
 "SNAPSHOT: the patch looks like this
+# generated by patch-package 0.0.0 on 1980-01-01 00:00:00
+#
+# command:
+#   npx patch-package @parcel/codeframe
+#
+# declared package:
+#   @parcel/codeframe: file:/mocked/path/to/codeframe-2.0.0-nightly.137.tgz#b8bfc2ccf223d6a26eaad193fc26c029f7e14d4f
+#
 diff --git a/node_modules/@parcel/codeframe/src/codeframe.js b/node_modules/@parcel/codeframe/src/codeframe.js
 index 2bf2c1c..ef0695b 100644
 --- a/node_modules/@parcel/codeframe/src/codeframe.js
diff --git a/integration-tests/nested-packages/__snapshots__/nested-packages.test.ts.snap b/integration-tests/nested-packages/__snapshots__/nested-packages.test.ts.snap
index 420488cc..18b3afa8 100644
--- a/integration-tests/nested-packages/__snapshots__/nested-packages.test.ts.snap
+++ b/integration-tests/nested-packages/__snapshots__/nested-packages.test.ts.snap
@@ -25,6 +25,14 @@ END SNAPSHOT"
 
 exports[`Test nested-packages: the patch file contents 1`] = `
 "SNAPSHOT: the patch file contents
+# generated by patch-package 0.0.0 on 1980-01-01 00:00:00
+#
+# command:
+#   npx patch-package wrap-ansi/string-width
+#
+# declared package:
+#   string-width: file:/mocked/path/to/string-width-2.1.1.tgz#ab93f27a8dc13d28cac815c462143a6d9012ae9e
+#
 diff --git a/node_modules/wrap-ansi/node_modules/string-width/index.js b/node_modules/wrap-ansi/node_modules/string-width/index.js
 index bbc49d2..6407f49 100644
 --- a/node_modules/wrap-ansi/node_modules/string-width/index.js
diff --git a/integration-tests/runIntegrationTest.ts b/integration-tests/runIntegrationTest.ts
index 3e788a2a..620e6303 100644
--- a/integration-tests/runIntegrationTest.ts
+++ b/integration-tests/runIntegrationTest.ts
@@ -7,7 +7,7 @@ import { resolveRelativeFileDependencies } from "../src/resolveRelativeFileDepen
 export const patchPackageTarballPath = resolve(
   fs
     .readdirSync(".")
-    .filter(nm => nm.match(/^patch-package\.test\.\d+\.tgz$/))[0],
+    .filter((nm) => nm.match(/^patch-package\.test\.\d+\.tgz$/))[0],
 )
 
 export function runIntegrationTest({
@@ -18,7 +18,10 @@ export function runIntegrationTest({
   shouldProduceSnapshots: boolean
 }) {
   describe(`Test ${projectName}:`, () => {
-    const tmpDir = tmp.dirSync({ unsafeCleanup: true })
+    const tmpDir = tmp.dirSync({
+      unsafeCleanup: true,
+      prefix: "patch-package.test-integration.",
+    })
     fs.copySync(join(__dirname, projectName), tmpDir.name, {
       recursive: true,
     })
@@ -64,7 +67,7 @@ export function runIntegrationTest({
         expect(snapshots && snapshots.length).toBeTruthy()
       })
       if (snapshots) {
-        snapshots.forEach(snapshot => {
+        snapshots.forEach((snapshot) => {
           const snapshotDescriptionMatch = snapshot.match(/SNAPSHOT: (.*)/)
           if (snapshotDescriptionMatch) {
             it(snapshotDescriptionMatch[1], () => {
@@ -80,5 +83,7 @@ export function runIntegrationTest({
         expect(snapshots && snapshots.length).toBeFalsy()
       })
     }
+
+    tmpDir.removeCallback()
   })
 }
diff --git a/package.json b/package.json
index bf67ee95..c87d76b9 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
-  "name": "patch-package",
-  "version": "6.4.7",
+  "name": "@milahu/patch-package-with-pnpm-support",
+  "version": "6.4.8",
   "description": "Fix broken node modules with no fuss",
   "main": "dist/index.js",
   "repository": "github:ds300/patch-package",
@@ -13,13 +13,14 @@
     "patch-package": "./index.js"
   },
   "scripts": {
-    "prepublishOnly": "yarn run clean && yarn run build",
+    "prepublishOnly": "npm run clean && npm run build",
     "build": "tsc --project tsconfig.build.json",
     "new-integration-test": "ts-node integration-tests/newIntegrationTest.ts",
     "clean": "rimraf dist patch-package.test*.tgz",
     "format": "prettier --no-semi --write --trailing-comma=all src{/**,}/*.ts integration-tests{/**,}/*.ts property-based-tests{/**,}/*.ts",
     "prepack": "rimraf dist/**/*.test.js",
-    "test": "./run-tests.sh --runInBand"
+    "test": "./run-tests.sh --runInBand",
+    "prepare": "npm run build"
   },
   "husky": {
     "hooks": {
@@ -54,13 +55,13 @@
     "@types/fs-extra": "^5.0.5",
     "@types/is-ci": "^1.1.0",
     "@types/jest": "^24.0.11",
-    "@types/minimist": "^1.2.0",
     "@types/node": "^11.11.6",
     "@types/rimraf": "^2.0.2",
     "@types/semver": "^5.5.0",
     "@types/tmp": "^0.0.34",
     "husky": "^1.3.1",
     "jest": "^24.5.0",
+    "js-yaml": "^4.0.0",
     "lint-staged": "^8.1.5",
     "np": "^7.4.0",
     "prettier": "^2.2.1",
@@ -71,17 +72,19 @@
     "typescript": "^4.2.2"
   },
   "dependencies": {
+    "@types/dashdash": "^1.14.0",
     "@yarnpkg/lockfile": "^1.1.0",
     "chalk": "^2.4.2",
     "cross-spawn": "^6.0.5",
+    "dashdash": "^2.0.0",
     "find-yarn-workspace-root": "^2.0.0",
     "fs-extra": "^7.0.1",
     "is-ci": "^2.0.0",
     "klaw-sync": "^6.0.0",
-    "minimist": "^1.2.0",
     "open": "^7.4.2",
     "rimraf": "^2.6.3",
     "semver": "^5.6.0",
+    "shlex": "^2.0.2",
     "slash": "^2.0.0",
     "tmp": "^0.0.33"
   },
diff --git a/property-based-tests/executeTestCase.ts b/property-based-tests/executeTestCase.ts
index 87d19a77..011b923e 100644
--- a/property-based-tests/executeTestCase.ts
+++ b/property-based-tests/executeTestCase.ts
@@ -24,32 +24,31 @@ jest.mock("fs-extra", () => {
     setWorkingFiles,
     getWorkingFiles,
     ensureDirSync: jest.fn(),
-    readFileSync: jest.fn(path => getWorkingFiles()[path].contents),
+    readFileSync: jest.fn((filePath) => getWorkingFiles()[filePath].contents),
     writeFileSync: jest.fn(
-      (path: string, contents: string, opts?: { mode?: number }) => {
-        getWorkingFiles()[path] = {
+      (filePath: string, contents: string, opts?: { mode?: number }) => {
+        getWorkingFiles()[filePath] = {
           contents,
           mode: opts && typeof opts.mode === "number" ? opts.mode : 0o644,
         }
       },
     ),
-    unlinkSync: jest.fn(path => delete getWorkingFiles()[path]),
+    unlinkSync: jest.fn((filePath) => delete getWorkingFiles()[filePath]),
     moveSync: jest.fn((from, to) => {
       getWorkingFiles()[to] = getWorkingFiles()[from]
       delete getWorkingFiles()[from]
     }),
-    statSync: jest.fn(path => getWorkingFiles()[path]),
-    chmodSync: jest.fn((path, mode) => {
-      const { contents } = getWorkingFiles()[path]
-      getWorkingFiles()[path] = { contents, mode }
+    statSync: jest.fn((filePath) => getWorkingFiles()[filePath]),
+    chmodSync: jest.fn((filePath, mode) => {
+      const { contents } = getWorkingFiles()[filePath]
+      getWorkingFiles()[filePath] = { contents, mode }
     }),
   }
 })
 
 function writeFiles(cwd: string, files: Files): void {
   const mkdirpSync = require("fs-extra/lib/mkdirs/index.js").mkdirpSync
-  const writeFileSync = require("fs").writeFileSync
-  Object.keys(files).forEach(filePath => {
+  Object.keys(files).forEach((filePath) => {
     if (!filePath.startsWith(".git/")) {
       mkdirpSync(path.join(cwd, path.dirname(filePath)))
       writeFileSync(path.join(cwd, filePath), files[filePath].contents, {
@@ -62,7 +61,7 @@ function writeFiles(cwd: string, files: Files): void {
 function removeLeadingSpaceOnBlankLines(patchFileContents: string): string {
   return patchFileContents
     .split("\n")
-    .map(line => (line === " " ? "" : line))
+    .map((line) => (line === " " ? "" : line))
     .join("\n")
 }
 
@@ -83,7 +82,11 @@ export function executeTestCase(testCase: TestCase) {
     }
   }
 
-  const tmpDir = tmp.dirSync({ unsafeCleanup: true, mode: 0o100777 })
+  const tmpDir = tmp.dirSync({
+    unsafeCleanup: true,
+    mode: 0o100777,
+    prefix: "patch-package.test-property.",
+  })
 
   spawnSafeSync("git", ["init"], { cwd: tmpDir.name })
 
@@ -145,4 +148,6 @@ export function executeTestCase(testCase: TestCase) {
       expect(fs.getWorkingFiles()).toEqual(testCase.cleanFiles)
     })
   })
+
+  tmpDir.removeCallback()
 }
diff --git a/property-based-tests/testCases.ts b/property-based-tests/testCases.ts
index 8fef3bb8..8875f754 100644
--- a/property-based-tests/testCases.ts
+++ b/property-based-tests/testCases.ts
@@ -121,7 +121,7 @@ function insertLinesIntoFile(file: File): File {
 function getUniqueFilename(files: Files) {
   let filename = makeFileName()
   const ks = Object.keys(files)
-  while (ks.some(k => k.startsWith(filename))) {
+  while (ks.some((k) => k.startsWith(filename))) {
     filename = makeFileName()
   }
   return filename
diff --git a/run-tests.sh b/run-tests.sh
index 894d5268..07ca4847 100755
--- a/run-tests.sh
+++ b/run-tests.sh
@@ -10,3 +10,6 @@ yarn version --new-version 0.0.0 --no-git-tag-version --no-commit-hooks
 yarn pack --filename patch-package.test.$(date +%s).tgz
 yarn version --new-version $version --no-git-tag-version --no-commit-hooks
 yarn jest "$@"
+
+# workaround for https://github.com/yarnpkg/yarn/issues/6685
+rm -rf /tmp/yarn--* || true
diff --git a/src/applyPatches.ts b/src/applyPatches.ts
index adbe2dc2..c2759c52 100644
--- a/src/applyPatches.ts
+++ b/src/applyPatches.ts
@@ -189,7 +189,7 @@ export function applyPatchesForApp({
           }),
         )
       }
-    } catch (error) {
+    } catch (error: any) {
       if (error instanceof PatchApplicationError) {
         errors.push(error.message)
       } else {
@@ -379,14 +379,15 @@ function createUnexpectedError({
   error,
 }: {
   filename: string
-  error: Error
+  error: any
 }) {
+  var stack = (error instanceof Error) ? error.stack : error
   return `
 ${chalk.red.bold("**ERROR**")} ${chalk.red(
     `Failed to apply patch file ${chalk.bold(filename)}`,
   )}
   
-${error.stack}
+${stack}
 
   `
 }
diff --git a/src/detectPackageManager.ts b/src/detectPackageManager.ts
index 00976527..1be8a810 100644
--- a/src/detectPackageManager.ts
+++ b/src/detectPackageManager.ts
@@ -4,7 +4,7 @@ import chalk from "chalk"
 import process from "process"
 import findWorkspaceRoot from "find-yarn-workspace-root"
 
-export type PackageManager = "yarn" | "npm" | "npm-shrinkwrap"
+export type PackageManager = "yarn" | "npm" | "npm-shrinkwrap" | "pnpm"
 
 function printNoYarnLockfileError() {
   console.error(`
@@ -64,6 +64,8 @@ export const detectPackageManager = (
     }
   } else if (yarnLockExists || findWorkspaceRoot()) {
     return "yarn"
+  } else if (fs.existsSync(join(appRootPath, "pnpm-lock.yaml"))) {
+    return "pnpm"
   } else {
     printNoLockfilesError()
     process.exit(1)
diff --git a/src/filterFiles.ts b/src/filterFiles.ts
index 60983b32..c707cd72 100644
--- a/src/filterFiles.ts
+++ b/src/filterFiles.ts
@@ -8,10 +8,10 @@ export function removeIgnoredFiles(
   excludePaths: RegExp,
 ) {
   klawSync(dir, { nodir: true })
-    .map(item => item.path.slice(`${dir}/`.length))
+    .map((item) => item.path.slice(`${dir}/`.length))
     .filter(
-      relativePath =>
+      (relativePath) =>
         !relativePath.match(includePaths) || relativePath.match(excludePaths),
     )
-    .forEach(relativePath => removeSync(join(dir, relativePath)))
+    .forEach((relativePath) => removeSync(join(dir, relativePath)))
 }
diff --git a/src/getPackageResolution.ts b/src/getPackageResolution.ts
index 5c8c158b..71431a6e 100644
--- a/src/getPackageResolution.ts
+++ b/src/getPackageResolution.ts
@@ -5,15 +5,21 @@ import { readFileSync, existsSync } from "fs-extra"
 import { parse as parseYarnLockFile } from "@yarnpkg/lockfile"
 import findWorkspaceRoot from "find-yarn-workspace-root"
 import { getPackageVersion } from "./getPackageVersion"
+//import { execSync } from "child_process"
+
+//const isVerbose = global.patchPackageIsVerbose
+const isDebug = global.patchPackageIsDebug
 
 export function getPackageResolution({
   packageDetails,
   packageManager,
   appPath,
+  appPackageJson,
 }: {
   packageDetails: PackageDetails
   packageManager: PackageManager
   appPath: string
+  appPackageJson: any
 }) {
   if (packageManager === "yarn") {
     let lockFilePath = "yarn.lock"
@@ -56,21 +62,125 @@ export function getPackageResolution({
       console.warn(
         `Ambigious lockfile entries for ${packageDetails.pathSpecifier}. Using version ${installedVersion}`,
       )
-      return installedVersion
+      return { version: installedVersion }
     }
 
     if (resolutions[0]) {
-      return resolutions[0]
+      return { version: resolutions[0] }
     }
 
     const resolution = entries[0][0].slice(packageDetails.name.length + 1)
 
     // resolve relative file path
     if (resolution.startsWith("file:.")) {
-      return `file:${resolve(appPath, resolution.slice("file:".length))}`
+      return {
+        version: `file:${resolve(appPath, resolution.slice("file:".length))}`,
+      }
     }
+    return { version: resolution }
+  } else if (packageManager === "pnpm") {
+    // WORKAROUND for pnpm bug? pnpm-lock.yaml says version 1.2.3 for linked packages, not link:../../path/to/package
+    const declaredVersion =
+      (appPackageJson.dependencies &&
+        appPackageJson.dependencies[packageDetails.name]) ||
+      (appPackageJson.devDependencies &&
+        appPackageJson.devDependencies[packageDetails.name])
+    if (isDebug) {
+      console.log(
+        `patch-package/getPackageResolution: declaredVersion = ${declaredVersion}`,
+      )
+    }
+
+    // TODO validate: declaredVersion must not be wildcard
+    return { version: declaredVersion }
 
-    return resolution
+    // TODO dont use lockfiles at all?
+    // package versions should be pinned in /package.json, so it works with all package managers at all times
+    /*
+    const lockfile = require("js-yaml").load(
+      require("fs").readFileSync(join(appPath, "pnpm-lock.yaml"), "utf8"),
+    )
+    if (isDebug) {
+      console.log(`patch-package/getPackageResolution: appPath = ${appPath}`)
+      console.log(`patch-package/getPackageResolution: packageDetails:`)
+      console.dir(packageDetails)
+      console.log(
+        `patch-package/getPackageResolution: packageDetails.name = ${packageDetails.name}`,
+      )
+      console.log(
+        `patch-package/getPackageResolution: lockfile.dependencies[packageDetails.name] = ${
+          lockfile.dependencies[packageDetails.name]
+        }`,
+      )
+      console.log(
+        `patch-package/getPackageResolution: lockfile.devDependencies[packageDetails.name] = ${
+          lockfile.devDependencies[packageDetails.name]
+        }`,
+      )
+    }
+    let resolvedVersion =
+      (lockfile.dependencies && lockfile.dependencies[packageDetails.name]) ||
+      (lockfile.devDependencies &&
+        lockfile.devDependencies[packageDetails.name])
+    if (declaredVersion.startsWith("link:")) {
+      // WORKAROUND
+      if (isDebug) {
+        console.log(
+          `patch-package/getPackageResolution: using declaredVersion ${declaredVersion}, not resolvedVersion ${resolvedVersion}`,
+        )
+      }
+      resolvedVersion = declaredVersion
+    }
+    if (isDebug) {
+      console.log(
+        `patch-package/getPackageResolution: resolvedVersion = ${resolvedVersion}`,
+      )
+    }
+    if (resolvedVersion.startsWith("link:")) {
+      const localPath = resolve(resolvedVersion.slice(5))
+      if (isVerbose) {
+        console.log(
+          `patch-package/getPackageResolution: pnpm installed ${packageDetails.name} from ${localPath}`,
+        )
+      }
+      if (existsSync(localPath + "/.git")) {
+        // we hope that the originCommit will be available for future downloads
+        // otherwise our patch will not work ...
+        // ideally, we would use the last stable release before originCommit from npm or github
+        function exec(cmd: string) {
+          return execSync(cmd, {
+            cwd: localPath,
+            windowsHide: true,
+            encoding: "utf8",
+          }).trim()
+        }
+        const originUrl = exec("git remote get-url origin")
+        // TODO what if the upstream repo is not called "origin"?
+        const originCommit = exec("git rev-parse origin/HEAD") // npm needs the long commit hash
+        resolvedVersion = `git+${originUrl}#${originCommit}`
+        if (isVerbose) {
+          console.log(
+            `patch-package/getPackageResolution: using ${packageDetails.name} version ${resolvedVersion} from git origin/HEAD in ${localPath}`,
+          )
+        }
+        return { version: resolvedVersion, originCommit }
+      }
+      const pkgJson = localPath + "/package.json"
+      if (existsSync(pkgJson)) {
+        resolvedVersion = require(pkgJson).version
+        console.warn(
+          `warning: using ${packageDetails.name} version ${resolvedVersion} from ${pkgJson}`,
+        )
+        return { version: resolvedVersion }
+      }
+    }
+    if (isVerbose) {
+      console.log(
+        `patch-package/getPackageResolution: using ${packageDetails.name} version ${resolvedVersion}`,
+      )
+    }
+    return { version: resolvedVersion }
+    */
   } else {
     const lockfile = require(join(
       appPath,
@@ -91,7 +201,7 @@ export function getPackageResolution({
         entry.dependencies && packageDetails.name in entry.dependencies,
     )
     const pkg = relevantStackEntry.dependencies[packageDetails.name]
-    return pkg.resolved || pkg.from || pkg.version
+    return { version: pkg.resolved || pkg.from || pkg.version }
   }
 }
 
@@ -107,6 +217,7 @@ if (require.main === module) {
       appPath: process.cwd(),
       packageDetails,
       packageManager: detectPackageManager(process.cwd(), null),
+      appPackageJson: {}, // TODO?
     }),
   )
 }
diff --git a/src/index.ts b/src/index.ts
index a4691a28..a2772799 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,31 +1,30 @@
 import chalk from "chalk"
 import process from "process"
-import minimist from "minimist"
+import dashdash from "dashdash"
 
-import { applyPatchesForApp } from "./applyPatches"
 import { getAppRootPath } from "./getAppRootPath"
-import { makePatch } from "./makePatch"
-import { makeRegExp } from "./makeRegExp"
-import { detectPackageManager } from "./detectPackageManager"
 import { join } from "./path"
-import { normalize, sep } from "path"
-import slash = require("slash")
-import isCi from "is-ci"
 
 const appPath = getAppRootPath()
-const argv = minimist(process.argv.slice(2), {
-  boolean: [
-    "use-yarn",
-    "case-sensitive-path-filtering",
-    "reverse",
-    "help",
-    "version",
-    "error-on-fail",
-    "create-issue",
-  ],
-  string: ["patch-dir"],
-})
-const packageNames = argv._
+
+var dashdashOptions = [
+  { name: "use-yarn", type: "bool" },
+  { name: "create-issue", type: "bool" },
+  { name: "case-sensitive-path-filtering", type: "bool" },
+  { name: "reverse", type: "bool" },
+  { names: ["help", "h"], type: "bool" },
+  { names: ["version", "v"], type: "bool" },
+  { name: "error-on-fail", type: "bool" },
+  { name: "verbose", type: "bool" },
+  { name: "debug", type: "bool" },
+  { name: "patch-dir", type: "string" },
+  { name: "include", type: "string" },
+  { name: "exclude", type: "string" },
+];
+
+const argv = dashdash.parse({ options: dashdashOptions });
+
+const packageNames = argv._args
 
 console.log(
   chalk.bold("patch-package"),
@@ -33,12 +32,29 @@ console.log(
   require(join(__dirname, "../package.json")).version,
 )
 
-if (argv.version || argv.v) {
+// used in imported modules
+const isDebug = global.patchPackageIsDebug = argv.debug
+global.patchPackageIsVerbose = isDebug || argv.verbose
+
+if (isDebug) {
+  console.log(`patch-package/index: argv:`)
+  console.dir(argv)
+}
+
+import { applyPatchesForApp } from "./applyPatches"
+import { makePatch } from "./makePatch"
+import { makeRegExp } from "./makeRegExp"
+import { detectPackageManager } from "./detectPackageManager"
+import { normalize, sep } from "path"
+import slash = require("slash")
+import isCi from "is-ci"
+
+if (argv.version) {
   // noop
-} else if (argv.help || argv.h) {
+} else if (argv.help) {
   printHelp()
 } else {
-  const patchDir = slash(normalize((argv["patch-dir"] || "patches") + sep))
+  const patchDir = slash(normalize((argv.patch_dir || "patches") + sep))
   if (patchDir.startsWith("/")) {
     throw new Error("--patch-dir must be a relative path")
   }
@@ -47,19 +63,23 @@ if (argv.version || argv.v) {
       argv.include,
       "include",
       /.*/,
-      argv["case-sensitive-path-filtering"],
+      argv.case_sensitive_path_filtering,
     )
     const excludePaths = makeRegExp(
       argv.exclude,
       "exclude",
       /package\.json$/,
-      argv["case-sensitive-path-filtering"],
+      argv.case_sensitive_path_filtering,
     )
     const packageManager = detectPackageManager(
       appPath,
-      argv["use-yarn"] ? "yarn" : null,
+      argv.use_yarn ? "yarn" : null,
     )
-    const createIssue = argv["create-issue"]
+    if (isDebug) {
+      console.log(`patch-package/index: packageManager = ${packageManager}`)
+    }
+
+    const createIssue = argv.create_issue
     packageNames.forEach((packagePathSpecifier: string) => {
       makePatch({
         packagePathSpecifier,
@@ -73,11 +93,11 @@ if (argv.version || argv.v) {
     })
   } else {
     console.log("Applying patches...")
-    const reverse = !!argv["reverse"]
+    const reverse = argv.reverse
     // don't want to exit(1) on postinsall locally.
     // see https://github.com/ds300/patch-package/issues/86
     const shouldExitWithError =
-      !!argv["error-on-fail"] || isCi || process.env.NODE_ENV === "test"
+      argv.error_on_fail || isCi || process.env.NODE_ENV === "test"
     applyPatchesForApp({ appPath, reverse, patchDir, shouldExitWithError })
   }
 }
diff --git a/src/makePatch.ts b/src/makePatch.ts
index 13696703..78f5fb2a 100644
--- a/src/makePatch.ts
+++ b/src/makePatch.ts
@@ -1,5 +1,6 @@
 import chalk from "chalk"
 import { join, dirname, resolve } from "./path"
+import { basename } from "path"
 import { spawnSafeSync } from "./spawnSafe"
 import { PackageManager } from "./detectPackageManager"
 import { removeIgnoredFiles } from "./filterFiles"
@@ -10,6 +11,11 @@ import {
   unlinkSync,
   mkdirpSync,
   realpathSync,
+  renameSync,
+  /*
+  lstatSync,
+  readlinkSync,
+  */
 } from "fs-extra"
 import { sync as rimraf } from "rimraf"
 import { copySync } from "fs-extra"
@@ -29,6 +35,11 @@ import {
   maybePrintIssueCreationPrompt,
   openIssueCreationLink,
 } from "./createIssue"
+import { quote as shlexQuote } from "shlex"
+
+const isVerbose = global.patchPackageIsVerbose
+const isDebug = global.patchPackageIsDebug
+const isTest = process.env.NODE_ENV == 'test'
 
 function printNoPackageFoundError(
   packageName: string,
@@ -68,36 +79,62 @@ export function makePatch({
   const packagePath = join(appPath, packageDetails.path)
   const packageJsonPath = join(packagePath, "package.json")
 
+  if (isDebug) {
+    console.log(`patch-package/makePatch: appPath = ${appPath}`)
+    console.log(`patch-package/makePatch: packagePath = ${packagePath}`)
+    console.log(`patch-package/makePatch: appPackageJson:`)
+    console.dir(appPackageJson)
+  }
+
   if (!existsSync(packageJsonPath)) {
     printNoPackageFoundError(packagePathSpecifier, packageJsonPath)
     process.exit(1)
   }
 
-  const tmpRepo = dirSync({ unsafeCleanup: true })
-  const tmpRepoPackagePath = join(tmpRepo.name, packageDetails.path)
-  const tmpRepoNpmRoot = tmpRepoPackagePath.slice(
-    0,
-    -`/node_modules/${packageDetails.name}`.length,
-  )
+  const tmpRepo = dirSync({
+    unsafeCleanup: true,
+    prefix: "patch-package.tmpRepo.",
+  })
 
-  const tmpRepoPackageJsonPath = join(tmpRepoNpmRoot, "package.json")
+  function cleanup() {
+    tmpRepo.removeCallback()
+  }
 
   try {
+    // finally: cleanup()
+
+    const tmpRepoPackagePath = join(tmpRepo.name, packageDetails.path)
+    const tmpRepoNpmRoot = tmpRepoPackagePath.slice(
+      0,
+      -`/node_modules/${packageDetails.name}`.length,
+    )
+
+    const tmpRepoPackageJsonPath = join(tmpRepoNpmRoot, "package.json")
+
     const patchesDir = resolve(join(appPath, patchDir))
 
     console.info(chalk.grey("•"), "Creating temporary folder")
 
+    if (isDebug) {
+      console.log(
+        `patch-package/makePatch: tmpRepoNpmRoot = ${tmpRepoNpmRoot}`,
+      )
+    }
+
+    const resolvedVersion = getPackageResolution({
+      packageDetails,
+      packageManager,
+      appPath,
+      appPackageJson,
+    })
+
     // make a blank package.json
     mkdirpSync(tmpRepoNpmRoot)
     writeFileSync(
       tmpRepoPackageJsonPath,
       JSON.stringify({
         dependencies: {
-          [packageDetails.name]: getPackageResolution({
-            packageDetails,
-            packageManager,
-            appPath,
-          }),
+          [packageDetails.name]: resolvedVersion.version,
         },
         resolutions: resolveRelativeFileDependencies(
           appPath,
@@ -106,9 +143,115 @@ export function makePatch({
       }),
     )
 
-    const packageVersion = getPackageVersion(
-      join(resolve(packageDetails.path), "package.json"),
+    const declaredVersion = (() => {
+      var v = resolvedVersion.version
+      // https://docs.npmjs.com/cli/v7/configuring-npm/package-json
+      // <protocol>://[<user>[:<password>]@]<hostname>[:<port>][:][/]<path>[#<commit-ish> | #semver:<semver>]
+      // pnpm uses link: protocol instead of file:
+      // TODO add more protocols?
+      var m = v.match(/^(file|link|http|https|git|git\+https|git\+http|git\+ssh|git\+file|github):(.+)$/)
+      if (m) {
+        var protocol = m[1]
+        var location = m[2]
+        var isGit = protocol.startsWith('git')
+        var gitCommit = (isGit && location.includes("#")) ? location.split('#').slice(-1)[0] : null
+        if (isDebug) {
+          console.dir({ loc: 'get declaredVersion', isGit, gitCommit });
+        }
+        if (isGit && !gitCommit) {
+          var error = new Error(`found wildcard git version ${v}. \
+package.json must pin the exact version of ${packageDetails.name} \
+in the format <protocol>:<packagePath>#<commitHash>. \
+commitHash is the full hash with 40 chars.`)
+          delete error.stack
+          throw error
+          /* too complex
+          // guess commit hash of installed package
+          var stats = lstatSync(packageDetails.path)
+          if (stats.isSymbolicLink()) {
+            var linkTarget = readlinkSync(packageDetails.path)
+            if (linkTarget.startsWith(".pnpm")) {
+              var match = linkTarget.match(/^\.pnpm\/[^/]+@([0-9a-f]{10})_[0-9a-f]{32}\//)
+              if (match) {
+                gitCommit = match[1]
+                if (isDebug) console.log(`parsed gitCommit ${gitCommit} from pnpm symlink`)
+              }
+            }
+          }
+          */
+        }
+        if (isGit) {
+          return { full: v, protocol, location, gitCommit }
+        }
+        else {
+          // sample: https://registry.yarnpkg.com/left-pad/-/left-pad-1.3.0.tgz#5b8a3a7765dfe001261dde915589e782f8c94d1e
+          // hash is sha1sum of tgz file
+          // -> use version number from package's package.json
+          var version = getPackageVersion(join(resolve(packageDetails.path), "package.json"))
+          if (isVerbose) {
+            console.log(`patch-package/makePatch: using version ${version} from ${packageDetails.name}/package.json`)
+          }
+          return { version }
+        }
+      }
+      // https://docs.npmjs.com/about-semantic-versioning
+      if (!v.match(/^[0-9]+\.[0-9]+\.[0-9]+$/)) {
+        var exactPart = v.match(/^[^~]([0-9]+\.[0-9]+\.[0-9]+)$/)
+        var exampleVersion = '1.2.3'
+        if (exactPart) {
+          exampleVersion = exactPart[1]
+        }
+        console.warn(`patch-package/makePatch: warning: found wildcard version. \
+to ensure successful patching, package.json should pin the exact version of ${packageDetails.name} \
+in the format <major>.<minor>.<patch>, for example: "${packageDetails.name}": "${exampleVersion}"`)
+      }
+      return { full: v, version: v }
+    })()
+
+    if (isDebug) {
+      //console.log(`patch-package/makePatch: resolvedVersion.originCommit = ${resolvedVersion.originCommit}`)
+      console.log(`patch-package/makePatch: declaredVersion.version = ${declaredVersion.version}`)
+      console.log(`patch-package/makePatch: declaredVersion.gitCommit = ${declaredVersion.gitCommit}`)
+      console.log(`patch-package/makePatch: declaredVersion.full = ${declaredVersion.full}`)
+    }
+
+    const packageVersion = (
+      declaredVersion.version || declaredVersion.gitCommit || declaredVersion.full
+    )
+
+    // originCommit is more precise than pkg.version
+    if (isDebug) {
+      //console.log(`patch-package/makePatch: resolvedVersion.originCommit = ${resolvedVersion.originCommit}`)
+      console.log(`patch-package/makePatch: resolvedVersion.version = ${resolvedVersion.version}`)
+      console.log(`patch-package/makePatch: packageVersion = ${packageVersion}`)
+    }
+
+    //const packageVersion =
+    //  resolvedVersion.originCommit ||
+    //  getPackageVersion(join(resolve(packageDetails.path), "package.json"))
+
+    // this is broken when installing from git -> version can be a pseudo-version like 1.0.0-canary
+    //const packageVersion = getPackageVersion(join(resolve(packageDetails.path), "package.json"))
+
+    // TODO rename resolvedVersion -> declaredVersion
+
+    // FIXME false positive
+    // test integration-tests/create-issue/create-issue.test.ts
+    // -> patching left-pad prompts to submit an issue
+    // https://registry.yarnpkg.com/left-pad/-/left-pad-1.3.0.tgz#5b8a3a7765dfe001261dde915589e782f8c94d1e
+    // hash is sha checksum of tgz file -> just use the version 1.3.0
+    /*
+    const packageVersion = (
+      !resolvedVersion.version.match(/^(file:|link:)/) ? resolvedVersion.version :
+      getPackageVersion(join(resolve(packageDetails.path), "package.json"))
     )
+    */
+
+    if (isDebug) {
+      console.log(`patch-package/makePatch: getPackageVersion -> ${getPackageVersion(join(resolve(packageDetails.path), "package.json"))}`)
+      console.log(`patch-package/makePatch: package path = ${packageDetails.path}`)
+      console.log(`patch-package/makePatch: package path resolved = ${resolve(packageDetails.path)}`)
+    }
 
     // copy .npmrc/.yarnrc in case packages are hosted in private registry
     // tslint:disable-next-line:align
@@ -131,7 +274,7 @@ export function makePatch({
           cwd: tmpRepoNpmRoot,
           logStdErrOnError: false,
         })
-      } catch (e) {
+      } catch (e: any) {
         // try again while ignoring scripts in case the script depends on
         // an implicit context which we havn't reproduced
         spawnSafeSync(
@@ -143,26 +286,44 @@ export function makePatch({
         )
       }
     } else {
+      const npmCmd = packageManager === "pnpm" ? "pnpm" : "npm"
       console.info(
         chalk.grey("•"),
-        `Installing ${packageDetails.name}@${packageVersion} with npm`,
+        `Installing ${packageDetails.name}@${packageVersion} with ${npmCmd}`,
       )
       try {
         // try first without ignoring scripts in case they are required
         // this works in 99.99% of cases
-        spawnSafeSync(`npm`, ["i", "--force"], {
+        if (isVerbose) {
+          console.log(
+            `patch-package/makePatch: run "${npmCmd} install --force" in ${tmpRepoNpmRoot}`,
+          )
+        }
+        spawnSafeSync(npmCmd, ["install", "--force"], {
           cwd: tmpRepoNpmRoot,
           logStdErrOnError: false,
-          stdio: "ignore",
+          stdio: isVerbose ? "inherit" : "ignore",
         })
-      } catch (e) {
+      } catch (e: any) {
         // try again while ignoring scripts in case the script depends on
         // an implicit context which we havn't reproduced
-        spawnSafeSync(`npm`, ["i", "--ignore-scripts", "--force"], {
+        if (isVerbose) {
+          console.log(
+            `patch-package/makePatch: run "${npmCmd} install --ignore-scripts --force" in ${tmpRepoNpmRoot}`,
+          )
+        }
+        spawnSafeSync(npmCmd, ["install", "--ignore-scripts", "--force"], {
           cwd: tmpRepoNpmRoot,
-          stdio: "ignore",
+          stdio: isVerbose ? "inherit" : "ignore",
         })
       }
+      if (packageManager === "pnpm") {
+        // workaround for `git diff`: replace symlink with hardlink
+        const pkgPath = tmpRepoNpmRoot + "/node_modules/" + packageDetails.name
+        const realPath = realpathSync(pkgPath)
+        unlinkSync(pkgPath) // rm symlink
+        renameSync(realPath, pkgPath)
+      }
     }
 
     const git = (...args: string[]) =>
@@ -185,6 +346,7 @@ export function makePatch({
     git("config", "--local", "user.email", "patch@pack.age")
 
     // remove ignored files first
+    // use CLI options --exclude and --include
     removeIgnoredFiles(tmpRepoPackagePath, includePaths, excludePaths)
 
     git("add", "-f", packageDetails.path)
@@ -193,8 +355,21 @@ export function makePatch({
     // replace package with user's version
     rimraf(tmpRepoPackagePath)
 
+    if (isVerbose) {
+      console.log(
+        `patch-package/makePatch: copy ${realpathSync(
+          packagePath,
+        )} to ${tmpRepoPackagePath}`,
+      )
+    }
+
     // pnpm installs packages as symlinks, copySync would copy only the symlink
-    copySync(realpathSync(packagePath), tmpRepoPackagePath)
+    const srcPath = realpathSync(packagePath)
+    copySync(srcPath, tmpRepoPackagePath, {
+      filter: (path) => {
+        return !path.startsWith(srcPath + "/node_modules/")
+      },
+    })
 
     // remove nested node_modules just to be safe
     rimraf(join(tmpRepoPackagePath, "node_modules"))
@@ -202,11 +377,14 @@ export function makePatch({
     rimraf(join(tmpRepoPackagePath, ".git"))
 
     // also remove ignored files like before
+    // use CLI options --exclude and --include
     removeIgnoredFiles(tmpRepoPackagePath, includePaths, excludePaths)
 
     // stage all files
     git("add", "-f", packageDetails.path)
 
+    const ignorePaths = ["package-lock.json", "pnpm-lock.yaml"]
+
     // get diff of changes
     const diffResult = git(
       "diff",
@@ -214,6 +392,9 @@ export function makePatch({
       "--no-color",
       "--ignore-space-at-eol",
       "--no-ext-diff",
+      ...ignorePaths.map(
+        (path) => `:(exclude,top)${packageDetails.path}/${path}`,
+      ),
     )
 
     if (diffResult.stdout.length === 0) {
@@ -221,15 +402,17 @@ export function makePatch({
         `⁉️  Not creating patch file for package '${packagePathSpecifier}'`,
       )
       console.warn(`⁉️  There don't appear to be any changes.`)
+      cleanup()
       process.exit(1)
       return
     }
 
     try {
       parsePatchFile(diffResult.stdout.toString())
-    } catch (e) {
+    } catch (e: any) {
+      if (!(e instanceof Error)) return
       if (
-        (e as Error).message.includes("Unexpected file mode string: 120000")
+        e.message.includes("Unexpected file mode string: 120000")
       ) {
         console.error(`
 ⛔️ ${chalk.red.bold("ERROR")}
@@ -272,6 +455,7 @@ export function makePatch({
 
 `)
       }
+      cleanup()
       process.exit(1)
       return
     }
@@ -284,6 +468,50 @@ export function makePatch({
       }
     })
 
+    const patchPackageVersion = require("../package.json").version
+
+    // patchfiles are parsed in patch/parse.ts function parsePatchLines
+    // -> header comments are ignored
+    let diffHeader = ""
+    const dateStr = (
+      isTest ? '1980-01-01 00:00:00' : // mock date
+      new Date().toLocaleString("lt")
+    )
+    diffHeader += `# generated by patch-package ${patchPackageVersion} on ${dateStr}\n`
+    diffHeader += `#\n`
+    const prettyArgv = process.argv.slice()
+    if (prettyArgv[0].match(/node/)) {
+      prettyArgv[0] = "npx"
+    }
+    if (prettyArgv[1].match(/patch-package/)) {
+      prettyArgv[1] = "patch-package"
+    }
+    diffHeader += `# command:\n`
+    diffHeader += `#   ${prettyArgv.map((a) => shlexQuote(a)).join(" ")}\n`
+    diffHeader += `#\n`
+    diffHeader += `# declared package:\n`
+    // TODO rename resolvedVersion.version to declaredVersion
+    const declaredPackageStr = (
+      isTest ? (() => {
+        const v = resolvedVersion.version
+        const b = basename(v)
+        if (b != v) return `file:/mocked/path/to/${b}` // mock path // TODO keep the relative path? as declared in /package.json. see getPackageResolution "resolve relative file path"
+        return v
+      })() :
+      resolvedVersion.version
+    )
+    diffHeader += `#   ${packageDetails.name}: ${declaredPackageStr}\n`
+    /* redundant. this is visible from command, sample: npx patch-package wrap-ansi/string-width -> packageNames: wrap-ansi, string-width
+    if (packageDetails.packageNames.length > 1) {
+      diffHeader += `#\n`
+      diffHeader += `# package names:\n`
+      packageDetails.packageNames.forEach((packageName) => {
+        diffHeader += `#   ${packageName}\n`
+      })
+    }
+    */
+    diffHeader += `#\n`
+
     const patchFileName = createPatchFileName({
       packageDetails,
       packageVersion,
@@ -291,10 +519,9 @@ export function makePatch({
 
     const patchPath = join(patchesDir, patchFileName)
     if (!existsSync(dirname(patchPath))) {
-      // scoped package
-      mkdirSync(dirname(patchPath))
+      mkdirSync(dirname(patchPath), { recursive: true })
     }
-    writeFileSync(patchPath, diffResult.stdout)
+    writeFileSync(patchPath, diffHeader + diffResult.stdout)
     console.log(
       `${chalk.green("✔")} Created file ${join(patchDir, patchFileName)}\n`,
     )
@@ -307,11 +534,11 @@ export function makePatch({
     } else {
       maybePrintIssueCreationPrompt(packageDetails, packageManager)
     }
-  } catch (e) {
-    console.error(e)
+  } catch (e: any) {
+    //console.error(e)
     throw e
   } finally {
-    tmpRepo.removeCallback()
+    cleanup()
   }
 }
 
diff --git a/src/packageIsDevDependency.ts b/src/packageIsDevDependency.ts
index 2719c9be..330cb83d 100644
--- a/src/packageIsDevDependency.ts
+++ b/src/packageIsDevDependency.ts
@@ -14,5 +14,7 @@ export function packageIsDevDependency({
     return false
   }
   const { devDependencies } = require(packageJsonPath)
-  return Boolean(devDependencies && devDependencies[packageDetails.packageNames[0]])
+  return Boolean(
+    devDependencies && devDependencies[packageDetails.packageNames[0]],
+  )
 }
diff --git a/src/patch/apply.ts b/src/patch/apply.ts
index c2601bae..0c21b61f 100644
--- a/src/patch/apply.ts
+++ b/src/patch/apply.ts
@@ -7,7 +7,7 @@ export const executeEffects = (
   effects: ParsedPatchFile,
   { dryRun }: { dryRun: boolean },
 ) => {
-  effects.forEach(eff => {
+  effects.forEach((eff) => {
     switch (eff.type) {
       case "file deletion":
         if (dryRun) {
diff --git a/src/patch/parse.ts b/src/patch/parse.ts
index 97fb533d..51ff53bd 100644
--- a/src/patch/parse.ts
+++ b/src/patch/parse.ts
@@ -175,7 +175,16 @@ function parsePatchLines(
     const line = lines[i]
 
     if (state === "parsing header") {
-      if (line.startsWith("@@")) {
+      if (line.startsWith("#")) {
+        // ignore metadata comment line in header
+        // in the unidiff format, all header lines before `--- a/` are comment lines
+        // git-diff uses these comment lines to store metadata
+        // https://stackoverflow.com/questions/18979120
+        if (global.patchPackageIsDebug) {
+          console.log(`patch-package/patch/parse: ignore comment line: ${line}`)
+        }
+        continue
+      } else if (line.startsWith("@@")) {
         state = "parsing hunks"
         currentFilePatch.hunks = []
         i--
@@ -206,9 +215,10 @@ function parsePatchLines(
       } else if (line.startsWith("rename to ")) {
         currentFilePatch.renameTo = line.slice("rename to ".length).trim()
       } else if (line.startsWith("index ")) {
-        const match = line.match(/(\w+)\.\.(\w+)/)
+        const match = line.match(/(\w+)\.\.(\w+)/) // TODO match whole line
+        //const match = line.match(/^index (\w+)\.\.(\w+)$/)
         if (!match) {
-          continue
+          continue // TODO handle parse error?
         }
         currentFilePatch.beforeHash = match[1]
         currentFilePatch.afterHash = match[2]
diff --git a/src/patchFs.ts b/src/patchFs.ts
index 9786365e..13d9d49c 100644
--- a/src/patchFs.ts
+++ b/src/patchFs.ts
@@ -5,7 +5,7 @@ export const getPatchFiles = (patchesDir: string) => {
   try {
     return klawSync(patchesDir, { nodir: true })
       .map(({ path }) => relative(patchesDir, path))
-      .filter(path => path.endsWith(".patch"))
+      .filter((path) => path.endsWith(".patch"))
   } catch (e) {
     return []
   }
diff --git a/src/spawnSafe.ts b/src/spawnSafe.ts
index 3ea042f7..baf7d8a3 100644
--- a/src/spawnSafe.ts
+++ b/src/spawnSafe.ts
@@ -1,35 +1,35 @@
-import { sync as spawnSync } from "cross-spawn"
-import { SpawnOptions } from "child_process"
-
-export interface SpawnSafeOptions extends SpawnOptions {
-  throwOnError?: boolean
-  logStdErrOnError?: boolean
-  maxBuffer?: number
-}
-
-const defaultOptions: SpawnSafeOptions = {
-  logStdErrOnError: true,
-  throwOnError: true,
-}
-
-export const spawnSafeSync = (
-  command: string,
-  args?: string[],
-  options?: SpawnSafeOptions,
-) => {
-  const mergedOptions = Object.assign({}, defaultOptions, options)
-  const result = spawnSync(command, args, options)
-  if (result.error || result.status !== 0) {
-    if (mergedOptions.logStdErrOnError) {
-      if (result.stderr) {
-        console.error(result.stderr.toString())
-      } else if (result.error) {
-        console.error(result.error)
-      }
-    }
-    if (mergedOptions.throwOnError) {
-      throw result
-    }
-  }
-  return result
-}
+import { sync as spawnSync } from "cross-spawn"
+import { SpawnOptions } from "child_process"
+
+export interface SpawnSafeOptions extends SpawnOptions {
+  throwOnError?: boolean
+  logStdErrOnError?: boolean
+  maxBuffer?: number
+}
+
+const defaultOptions: SpawnSafeOptions = {
+  logStdErrOnError: true,
+  throwOnError: true,
+}
+
+export const spawnSafeSync = (
+  command: string,
+  args?: string[],
+  options?: SpawnSafeOptions,
+) => {
+  const mergedOptions = Object.assign({}, defaultOptions, options)
+  const result = spawnSync(command, args, options)
+  if (result.error || result.status !== 0) {
+    if (mergedOptions.logStdErrOnError) {
+      if (result.stderr) {
+        console.error(result.stderr.toString())
+      } else if (result.error) {
+        console.error(result.error)
+      }
+    }
+    if (mergedOptions.throwOnError) {
+      throw result
+    }
+  }
+  return result
+}
diff --git a/src/types/nodejs.global.d.ts b/src/types/nodejs.global.d.ts
new file mode 100644
index 00000000..fd1fe845
--- /dev/null
+++ b/src/types/nodejs.global.d.ts
@@ -0,0 +1,6 @@
+declare namespace NodeJS {
+  interface Global {
+    patchPackageIsVerbose: boolean
+    patchPackageIsDebug: boolean
+  }
+}
diff --git a/tslint.json b/tslint.json
index ea76ddb6..e33715fa 100644
--- a/tslint.json
+++ b/tslint.json
@@ -17,7 +17,9 @@
     "no-trailing-whitespace": [false],
     "object-literal-key-quotes": [false],
     "max-line-length": false,
-    "no-default-export": true
+    "no-default-export": true,
+    "no-namespace": false,
+    "comment-format": false
   },
   "rulesDirectory": []
 }