sqlite3.OperationalError: disk I/O error

Crash Report

$ mypy . --show-traceback
error: INTERNAL ERROR -- Please try using mypy master on GitHub:
https://mypy.readthedocs.io/en/stable/common_issues.html#using-a-development-mypy-build
Please report a bug at https://github.com/python/mypy/issues
version: 2.3.1
Traceback (most recent call last):
  File "/tmp/py/lib/python3.14/site-packages/mypy/__main__.py", line 16, in console_entry
    main()
    ~~~~^^
  File "mypy/main.py", line 154, in main
  File "mypy/main.py", line 244, in run_build
    res = build.build(sources, options, None, flush_errors, fscache, stdout, stderr)
  File "mypy/build.py", line 385, in build
  File "mypy/build.py", line 1908, in create_metastore
    mds: MetadataStore = SqliteMetadataStore(
  File "mypy/metastore.py", line 200, in __init__
  File "mypy/metastore.py", line 172, in connect_db
    db.execute("PRAGMA synchronous=OFF")
sqlite3.OperationalError: disk I/O error

note: use --pdb to drop into pdb

To Reproduce

Source files are in a network mount:

$ mount | grep src
src on /home/hugo/src type 9p (rw,relatime,access=client,trans=virtio)

Sources are readable, execute fine, can be checked with ruff, etc.

You can quickly run a VM to reproduce this via:

qemu-system-x86_64 \
	--enable-kvm \
	-nic user \
	-nographic \
	-m 4G \
	-smp cores=2 \
        -drive file=alpine-virt-3.24.1-x86_64.iso,format=raw \                                                                                                                                                                                 
	-virtfs local,path=$HOME/src/,mount_tag=src,security_model=mapped-xattr

Then install mypy, mount the shared filesystem, and run it on any code in that fs.

Your Environment

• Mypy version used: mypy 2.3.1 (compiled: yes)
• Mypy command-line flags: (none/any)
• Mypy configuration options from mypy.ini (and other config files): irrelevant; always happens
• Python version used: Python 3.14.7
• Operating system and version: Alpine Linux Edge

Inizia da mypy/metastore.py, in particolare da connect_db e create_metastore, dove il traceback raggiunge PRAGMA synchronous=OFF. Riproduci il problema con la VM Alpine fornita e l’albero dei sorgenti montato tramite 9p, quindi esamina il comportamento del database dei metadati su quel mount. Il lavoro sarà considerato completato dopo aver verificato che mypy non termini più con questo sqlite3.OperationalError interno nell’ambiente segnalato.