Add value of UV_PYTHON_INSTALL_DIR to path (#628)

Closes: #610

src/cache/restore-cache.ts

@@ -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);

src/save-cache.ts

@@ -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/setup-uv.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/utils/inputs.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 {