init fails: "ImportError: cannot import name..."

[yanayz]

can't get past init stage...

new install via
claude mcp add semble -s user -- uvx --from "semble[mcp]" semble

run init in repo with
'semble init'

output:

Traceback (most recent call last):
  File "/Users/x/.local/bin/semble", line 4, in <module>
    from semble.cli import main
  File "/Users/x/.local/share/uv/tools/semble/lib/python3.13/site-packages/semble/__init__.py", line 1, in <module>
    from semble.index import SembleIndex
  File "/Users/x/.local/share/uv/tools/semble/lib/python3.13/site-packages/semble/index/__init__.py", line 1, in <module>
    from semble.index.index import SembleIndex
  File "/Users/x/.local/share/uv/tools/semble/lib/python3.13/site-packages/semble/index/index.py", line 13, in <module>
    from semble.index.create import create_index_from_path
  File "/Users/x/.local/share/uv/tools/semble/lib/python3.13/site-packages/semble/index/create.py", line 7, in <module>
    from semble.chunking import chunk_source
  File "/Users/x/.local/share/uv/tools/semble/lib/python3.13/site-packages/semble/chunking/__init__.py", line 1, in <module>
    from semble.chunking.chunking import chunk_source
  File "/Users/x/.local/share/uv/tools/semble/lib/python3.13/site-packages/semble/chunking/chunking.py", line 3, in <module>
    from semble.chunking.core import chunk, chunk_lines, is_supported_language
  File "/Users/x/.local/share/uv/tools/semble/lib/python3.13/site-packages/semble/chunking/core.py", line 8, in <module>
    from tree_sitter_language_pack import SupportedLanguage, get_parser, manifest_languages
ImportError: cannot import name 'SupportedLanguage' from 'tree_sitter_language_pack' (/Users/x/.local/share/uv/tools/semble/lib/python3.13/site-packages/tree_sitter_language_pack/__init__.py)

[kevicency]

Hit the same thing today. Root cause is upstream: tree-sitter-language-pack 1.8.0 removed the SupportedLanguage export that semble/chunking/core.py imports. semble 0.1.4 pins tree-sitter-language-pack!=1.6.3 with no upper bound, so uvx happily resolves to the broken 1.8.0.

Workaround — pin TSLP back to 1.6.2 in the MCP entry:

claude mcp remove semble -s user
claude mcp add semble -s user -- uvx --with "tree-sitter-language-pack==1.6.2" --from "semble[mcp]" semble

(Confirmed working: claude mcp list → semble: ... ✓ Connected.)

Proper fix would be either:

• Cap the dep in pyproject.toml (tree-sitter-language-pack>=1.0,<1.8), or
• Update semble/chunking/core.py to the new TSLP 1.8 API (SupportedLanguage was replaced — Language / LanguageInfo look like the new equivalents based on the 1.8.0 exports).

[Pringled]

Hey @yanayz and @kevicency thanks for reporting, this is indeed an issue in the newest release, I'm fixing this right now and releasing a new version.

[yanayz]

got it. looking forward to testing when resolved

[Pringled]

@yanayz @kevicency fixed in #87 and just released this (https://github.com/MinishLab/semble/releases/tag/v0.1.5). Thanks for the quick reporting on this! Unfortunately tree-sitter-language-pack introduced an API break without a major version bump. We've pinned it correctly now, I've also reported this on their repo. Let me know if everything works again and then I'll close this issue.

[yanayz]

silly question: how do I know it's actually working? that Claude is actually using it and not defaulting back to grep?

[Pringled]

@yanayz you can check how often your agent has called semble with the semble savings command, see https://github.com/MinishLab/semble#savings. This is useful for checking if it's actively being used. We are planning to add some better logging/monitoring for this as well in the future.