One post tagged with "curl"

After a major VSCode upgrade, the Claude Code extension becomes unresponsive for extended periods. The only option is to uninstall and reinstall — but then you hit Failed to fetch, VSIX format errors, and a series of other installation issues.

TL;DR​

After a VSCode upgrade, the extension may become unresponsive. Uninstalling and reinstalling reports Failed to fetch, and manually downloading the VSIX hits format errors. Root cause: the marketplace server returns gzip-compressed content (standard HTTP content negotiation), and curl -L may not auto-decompress when following redirects — the saved file ends up as gzip instead of zip. Fix: manual curl download → gunzip decompress → code --install-extension.

Symptoms​

After upgrading VSCode:

1. Claude Code conversations become unresponsive, stuck at Manifesting...
2. Clicking the extension icon takes forever to open a dialog
3. The only option is to uninstall and reinstall — but every install method fails

After uninstalling, all reinstall attempts fail:

# VSCode UI install → Failed to fetch
# Command line install → same error
code --install-extension anthropic.claude-code
# Error installing extension: Failed to fetch

Root Cause​

Three factors combine to cause this issue:

VSCode upgrade triggers WSL extension host reinitialization. Extensions like Claude Code must be installed on the WSL side to run (defined as remote extension host extensions). After a major upgrade, the extension may become unresponsive and require uninstalling and reinstalling.

VSCode extension installation uses its own network stack, ignoring WSL's http_proxy. Even with a proxy configured in WSL (e.g., http://172.30.0.1:7897), VSCode's extension download channel uses its own networking, unaffected by system proxy variables.

Marketplace server returns gzip-compressed content, curl -L doesn't auto-decompress. The marketplace API endpoint returns gzip-compressed responses via HTTP content negotiation — this is standard behavior. When curl -L follows redirects, it may not automatically decompress Content-Encoding: gzip, so the saved file ends up as gzip format instead of the expected zip format. Running file on the download shows gzip compressed data instead of Zip archive data.

Solution​

1. Download VSIX manually​

Use curl in the WSL terminal:

curl -L "https://marketplace.visualstudio.com/_apis/public/gallery/publishers/anthropic/vsextensions/claude-code/latest/vspackage" \
  -o ~/claude-code.vsix

2. Check file format​

file ~/claude-code.vsix

If the output is gzip compressed data, the file is gzip format — proceed to decompress. If it says Zip archive data, you have the raw format and can skip the next step.

3. Decompress to restore zip format​

gunzip -c ~/claude-code.vsix > ~/claude-code-real.vsix

Confirm the format is correct:

file ~/claude-code-real.vsix
# Output: Zip archive data, at least v2.0 to extract

4. Verify version (optional)​

unzip -p ~/claude-code-real.vsix extension/package.json | python3 -c "import json,sys; d=json.load(sys.stdin); print(d['version'])"

5. Install​

code --install-extension ~/claude-code-real.vsix

After installation, reload the VSCode window (Ctrl+Shift+P → Reload Window) to restore the extension.

WSL2 environment issues like this are common — if you've also encountered Docker Desktop host network mode ports unreachable from the host, it's similarly related to WSL2's unique architecture.

FAQ​

Is the VSCode extension "Failed to fetch" error caused by a proxy?​

Not necessarily. The marketplace server itself returns gzip-compressed content via standard HTTP content negotiation, and curl -L may not auto-decompress when following redirects. Manual download and gunzip decompression before installing bypasses this.

What to do when WSL extensions become unresponsive after a VSCode upgrade?​

Major VSCode upgrades reinitialize the WSL remote extension host, which may cause extensions to become unresponsive. Uninstall, download the VSIX manually, and install with code --install-extension to restore it.

VSIX install reports "not a zip file" — what now?​

The file is in gzip format instead of zip. The marketplace server returns gzip-compressed content, and curl -L may not auto-decompress. Decompress with gunzip -c file.vsix.gz > file.vsix before installing, and use the file command to verify the format.