From 985545dc34d967d53806e58a3225999cf99f53af Mon Sep 17 00:00:00 2001
From: Brian Krabach <brkrabac@microsoft.com>
Date: Sun, 25 Jan 2026 19:31:54 -0800
Subject: [PATCH] fix: add --force flag to uv cache clean to prevent deadlock
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The `amplifier reset` command was hanging indefinitely while cleaning
the UV cache because `uv cache clean` without `--force` waits for an
exclusive lock on the cache directory. Since amplifier itself runs as
a uv-installed tool, the cache is always "in use" when running
`amplifier reset`, causing an unresolvable deadlock.

Changes:
- Added `--force` flag to bypass the in-use check (per uv's docs)
- Added a 60-second timeout as a safeguard
- Added handling for `subprocess.TimeoutExpired` exception
- Updated docstring to explain why `--force` is required

🤖 Generated with [Amplifier](https://github.com/microsoft/amplifier)

Co-Authored-By: Amplifier <240397093+microsoft-amplifier@users.noreply.github.com>
---
 amplifier_app_cli/commands/reset.py | 19 ++++++++++++++++---
 1 file changed, 16 insertions(+), 3 deletions(-)

diff --git a/amplifier_app_cli/commands/reset.py b/amplifier_app_cli/commands/reset.py
index f9e295ca..8ec1110d 100644
--- a/amplifier_app_cli/commands/reset.py
+++ b/amplifier_app_cli/commands/reset.py
@@ -141,16 +141,29 @@ def _show_plan(
 
 
 def _clean_uv_cache(dry_run: bool = False) -> bool:
-    """Run 'uv cache clean'."""
+    """Run 'uv cache clean --force'.
+
+    The --force flag is required because amplifier itself runs as a uv-installed tool.
+    Without --force, uv cache clean waits indefinitely for an exclusive lock that
+    can never be acquired while the current process is running.
+    """
     console.print("[bold]>>>[/bold] Cleaning UV cache...")
 
     if dry_run:
-        console.print("    [dim][dry-run] Would run: uv cache clean[/dim]")
+        console.print("    [dim][dry-run] Would run: uv cache clean --force[/dim]")
         return True
 
     try:
-        subprocess.run(["uv", "cache", "clean"], check=True, capture_output=True)
+        subprocess.run(
+            ["uv", "cache", "clean", "--force"],
+            check=True,
+            capture_output=True,
+            timeout=60,  # Safeguard timeout
+        )
         return True
+    except subprocess.TimeoutExpired:
+        console.print("[yellow]Warning:[/yellow] UV cache clean timed out")
+        return False
     except subprocess.CalledProcessError as e:
         console.print(f"[yellow]Warning:[/yellow] Failed to clean UV cache: {e}")
         return False