Python: Require interpreter to have openrewrite installed for dev builds

Instead of silently bootstrapping a stale PyPI release into a `dev/`
directory, dev builds now require the Python interpreter to already
have the openrewrite package available. This is the expected setup
when using a venv created by `uv sync` in rewrite-python/rewrite/.

Release builds continue to bootstrap a pinned version into a
version-specific subdirectory under pipPackagesPath.

Author: knutwannheden

rewrite-python/src/main/java/org/openrewrite/python/rpc/PythonRewriteRpc.java

@@ -536,23 +536,25 @@ public Builder pythonVersion(String pythonVersion) {
 
         @Override
         public PythonRewriteRpc get() {
-            // For dev builds (version ending in .dev0), check whether the interpreter
-            // already has the rewrite package (e.g., from a venv with an editable install).
-            // If so, skip bootstrap and PYTHONPATH prepend so the interpreter's own
-            // version takes precedence. For release/CI builds, always use pipPackagesPath
-            // to ensure the correct pinned version.
             String version = StringUtils.readFully(
                     PythonRewriteRpc.class.getResourceAsStream("/META-INF/rewrite-python-version.txt")).trim();
             boolean isDevBuild = version.isEmpty() || version.endsWith(".dev0");
-            boolean interpreterHasRewrite = isDevBuild && pipPackagesPath != null && canImportRewrite(pythonPath);
-            boolean usePipPackagesPath = pipPackagesPath != null && !interpreterHasRewrite;
 
-            // Resolve version-specific subdirectory under pipPackagesPath
+            // For dev builds, require the interpreter already has the rewrite package
+            // (e.g., from a venv with an editable install via `uv sync`).
+            // For release builds, bootstrap into a version-specific subdirectory.
             Path resolvedPipPackagesPath = null;
-            if (usePipPackagesPath) {
-                String versionDir = isDevBuild ? "dev" : version;
-                resolvedPipPackagesPath = pipPackagesPath.resolve(versionDir);
-                bootstrapOpenrewrite(resolvedPipPackagesPath, version, isDevBuild);
+            if (isDevBuild) {
+                if (!canImportRewrite(pythonPath)) {
+                    throw new IllegalStateException(
+                            "The Python interpreter at " + pythonPath + " cannot import the 'rewrite' package. " +
+                            "For development builds, the interpreter must already have the openrewrite package installed. " +
+                            "Run 'uv sync' in the rewrite-python/rewrite/ directory to set up an editable install, " +
+                            "then configure the pythonPath to point to the venv's Python executable.");
+                }
+            } else if (pipPackagesPath != null) {
+                resolvedPipPackagesPath = pipPackagesPath.resolve(version);
+                bootstrapOpenrewrite(resolvedPipPackagesPath, version);
             }
 
             Stream<@Nullable String> cmd;
@@ -594,9 +596,8 @@ public PythonRewriteRpc get() {
             // If debug source path is set, use it
             if (debugRewriteSourcePath != null) {
                 pythonPathParts.add(debugRewriteSourcePath.toAbsolutePath().normalize().toString());
-            } else if (pipPackagesPath == null) {
-                // Only search for development source if pip packages path is not set
-                // Try to find the Python source in the project structure
+            } else if (isDevBuild) {
+                // For dev builds, try to find the Python source in the project structure
                 // Look for rewrite-python/rewrite/src relative to the working directory
                 Path basePath = workingDirectory != null ? workingDirectory : Paths.get(System.getProperty("user.dir"));
 
@@ -661,18 +662,12 @@ private static boolean canImportRewrite(Path pythonPath) {
         }
 
         /**
-         * Ensures the openrewrite Python package is installed in the pip packages directory.
-         * This is required for the RPC server to start.
+         * Ensures the pinned openrewrite Python package is installed in the pip packages directory.
+         * Only used for release builds — dev builds require the interpreter to already have the package.
          */
-        private void bootstrapOpenrewrite(Path pipPackagesPath, String version, boolean isDevBuild) {
-            boolean pinVersion = !isDevBuild;
-
+        private void bootstrapOpenrewrite(Path pipPackagesPath, String version) {
             Path versionMarker = pipPackagesPath.resolve(".openrewrite-version");
             if (Files.exists(pipPackagesPath.resolve("rewrite"))) {
-                // Already installed — check if version matches
-                if (!pinVersion) {
-                    return;
-                }
                 try {
                     if (Files.exists(versionMarker) &&
                             version.equals(new String(Files.readAllBytes(versionMarker), StandardCharsets.UTF_8).trim())) {
@@ -683,8 +678,6 @@ private void bootstrapOpenrewrite(Path pipPackagesPath, String version, boolean
                 }
             }
 
-            String packageSpec = pinVersion ? "openrewrite==" + version : "openrewrite";
-
             try {
                 Files.createDirectories(pipPackagesPath);
 
@@ -693,7 +686,7 @@ private void bootstrapOpenrewrite(Path pipPackagesPath, String version, boolean
                         "-m", "pip", "install",
                         "--upgrade",
                         "--target=" + pipPackagesPath.toAbsolutePath().normalize(),
-                        packageSpec
+                        "openrewrite==" + version
                 );
                 pb.redirectErrorStream(true);
                 if (log != null) {
@@ -727,10 +720,7 @@ private void bootstrapOpenrewrite(Path pipPackagesPath, String version, boolean
                     throw new RuntimeException("Failed to bootstrap openrewrite package, pip install exited with code " + exitCode);
                 }
 
-                // Write version marker so we can detect stale installs
-                if (pinVersion) {
-                    Files.write(versionMarker, version.getBytes(StandardCharsets.UTF_8));
-                }
+                Files.write(versionMarker, version.getBytes(StandardCharsets.UTF_8));
             } catch (IOException e) {
                 throw new UncheckedIOException("Failed to bootstrap openrewrite package", e);
             } catch (InterruptedException e) {