Add value of UV_PYTHON_INSTALL_DIR to path (#628)

Closes: #610

Author: eifinger

.github/workflows/test.yml

@@ -852,7 +852,7 @@ jobs:
           persist-credentials: false
       - name: Verify Python install dir is not populated
         run: |
-          if [ -d ~/.local/share/uv/python ]; then
+          if [ -d /home/runner/work/_temp/uv-python-dir ]; then
             echo "Python install dir should not exist"
             exit 1
           fi
@@ -866,7 +866,7 @@ jobs:
         working-directory: __tests__/fixtures/uv-project
       - name: Verify Python install dir exists
         run: |
-          if [ ! -d ~/.local/share/uv/python ]; then
+          if [ ! -d /home/runner/work/_temp/uv-python-dir ]; then
             echo "Python install dir should exist"
             exit 1
           fi
@@ -879,7 +879,7 @@ jobs:
           persist-credentials: false
       - name: Verify Python install dir does not exist
         run: |
-          if [ -d ~/.local/share/uv/python ]; then
+          if [ -d /home/runner/work/_temp/uv-python-dir ]; then
             echo "Python install dir should not exist"
             exit 1
           fi
@@ -892,7 +892,7 @@ jobs:
           cache-suffix: ${{ github.run_id }}-${{ github.run_attempt }}-test-cache-python-installs
       - name: Verify Python install dir exists
         run: |
-          if [ ! -d ~/.local/share/uv/python ]; then
+          if [ ! -d /home/runner/work/_temp/uv-python-dir ]; then
             echo "Python install dir should exist"
             exit 1
           fi
@@ -906,6 +906,34 @@ jobs:
       - run: uv sync --managed-python
         working-directory: __tests__/fixtures/uv-project
 
+  test-python-install-dir:
+    strategy:
+      matrix:
+        inputs:
+          - os: ubuntu-latest
+            expected-python-dir: "/home/runner/work/_temp/uv-python-dir"
+          - os: windows-latest
+            expected-python-dir: "D:\\a\\_temp\\uv-python-dir"
+          - os: selfhosted-ubuntu-arm64
+            expected-python-dir: "/home/ubuntu/.local/share/uv/python"
+    runs-on: ${{ matrix.inputs.os }}
+    steps:
+      - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
+        with:
+          persist-credentials: false
+      - name: Install latest version
+        id: setup-uv
+        uses: ./
+      - name: Check Python dir is expected dir
+        run: |
+          if [ "$UV_PYTHON_INSTALL_DIR" != "${{ matrix.inputs.expected-python-dir }}" ]; then
+            echo "Wrong UV_PYTHON_INSTALL_DIR: UV_PYTHON_INSTALL_DIR"
+            exit 1
+          fi
+        shell: bash
+      - name: Install python works
+        run: uv python install
+
   all-tests-passed:
     runs-on: ubuntu-latest
     needs:
@@ -950,6 +978,7 @@ jobs:
       - test-cache-dir-from-file
       - test-cache-python-installs
       - test-restore-python-installs
+      - test-python-install-dir
     if: always()
     steps:
       - name: All tests passed

dist/save-cache/index.js

@@ -7,8 +7,8 @@ import {
   cacheLocalPath,
   cachePython,
   cacheSuffix,
-  getUvPythonDir,
   pruneCache,
+  pythonDir,
   pythonVersion as pythonVersionInput,
   restoreCache as shouldRestoreCache,
   workingDirectory,
@@ -34,7 +34,7 @@ export async function restoreCache(): Promise<void> {
   );
   const cachePaths = [cacheLocalPath];
   if (cachePython) {
-    cachePaths.push(await getUvPythonDir());
+    cachePaths.push(pythonDir);
   }
   try {
     matchedKey = await cache.restoreCache(cachePaths, cacheKey);

dist/setup/index.js

@@ -12,8 +12,8 @@ import {
   cacheLocalPath,
   cachePython,
   enableCache,
-  getUvPythonDir,
   ignoreNothingToCache,
+  pythonDir,
   pruneCache as shouldPruneCache,
   saveCache as shouldSaveCache,
 } from "./utils/inputs";
@@ -73,7 +73,6 @@ async function saveCache(): Promise<void> {
 
   const cachePaths = [actualCachePath];
   if (cachePython) {
-    const pythonDir = await getUvPythonDir();
     core.info(`Including Python cache path: ${pythonDir}`);
     if (!fs.existsSync(pythonDir) && !ignoreNothingToCache) {
       throw new Error(

src/cache/restore-cache.ts

@@ -19,6 +19,7 @@ import {
   githubToken,
   ignoreEmptyWorkdir,
   manifestFile,
+  pythonDir,
   pythonVersion,
   toolBinDir,
   toolDir,
@@ -51,6 +52,7 @@ async function run(): Promise<void> {
     addToolBinToPath();
     addUvToPathAndOutput(setupResult.uvDir);
     setToolDir();
+    addPythonDirToPath();
     setupPython();
     await activateEnvironment();
     addMatchers();
@@ -194,6 +196,17 @@ function setToolDir(): void {
   }
 }
 
+function addPythonDirToPath(): void {
+  core.exportVariable("UV_PYTHON_INSTALL_DIR", pythonDir);
+  core.info(`Set UV_PYTHON_INSTALL_DIR to ${pythonDir}`);
+  if (process.env.UV_NO_MODIFY_PATH !== undefined) {
+    core.info("UV_NO_MODIFY_PATH is set, not adding python dir to path");
+  } else {
+    core.addPath(pythonDir);
+    core.info(`Added ${pythonDir} to the path`);
+  }
+}
+
 function setupPython(): void {
   if (pythonVersion !== "") {
     core.exportVariable("UV_PYTHON", pythonVersion);

src/save-cache.ts

@@ -1,6 +1,5 @@
 import path from "node:path";
 import * as core from "@actions/core";
-import * as exec from "@actions/exec";
 import { getConfigValueFromTomlFile } from "./config-file";
 
 export const workingDirectory = core.getInput("working-directory");
@@ -23,6 +22,7 @@ export const ignoreEmptyWorkdir =
   core.getInput("ignore-empty-workdir") === "true";
 export const toolBinDir = getToolBinDir();
 export const toolDir = getToolDir();
+export const pythonDir = getUvPythonDir();
 export const githubToken = core.getInput("github-token");
 export const manifestFile = getManifestFile();
 export const addProblemMatchers =
@@ -125,23 +125,26 @@ function getCacheDirFromConfig(): string | undefined {
   return undefined;
 }
 
-export async function getUvPythonDir(): Promise<string> {
+export function getUvPythonDir(): string {
   if (process.env.UV_PYTHON_INSTALL_DIR !== undefined) {
     core.info(
-      `Using UV_PYTHON_INSTALL_DIR from environment: ${process.env.UV_PYTHON_INSTALL_DIR}`,
+      `UV_PYTHON_INSTALL_DIR is already set to  ${process.env.UV_PYTHON_INSTALL_DIR}`,
     );
     return process.env.UV_PYTHON_INSTALL_DIR;
   }
-  core.info("Determining uv python dir using `uv python dir`...");
-  const result = await exec.getExecOutput("uv", ["python", "dir"]);
-  if (result.exitCode !== 0) {
-    throw new Error(
-      `Failed to get uv python dir: ${result.stderr || result.stdout}`,
-    );
+  if (process.env.RUNNER_ENVIRONMENT !== "github-hosted") {
+    if (process.platform === "win32") {
+      return `${process.env.APPDATA}${path.sep}uv${path.sep}python`;
+    } else {
+      return `${process.env.HOME}${path.sep}.local${path.sep}share${path.sep}uv${path.sep}python`;
+    }
   }
-  const dir = result.stdout.trim();
-  core.info(`Determined uv python dir: ${dir}`);
-  return dir;
+  if (process.env.RUNNER_TEMP !== undefined) {
+    return `${process.env.RUNNER_TEMP}${path.sep}uv-python-dir`;
+  }
+  throw Error(
+    "Could not determine UV_PYTHON_INSTALL_DIR. Please make sure RUNNER_TEMP is set or provide the UV_PYTHON_INSTALL_DIR environment variable",
+  );
 }
 
 function getCacheDependencyGlob(): string {