stack overflow in exact?

Stream: general

[Sebastien Gouezel]

Using exact? in an advanced file results for me in a stack overflow, with the following message:

Server process for file:///c%3A/Users/sebas/Desktop/mathlib4/Mathlib/Analysis/Calculus/BumpFunctionInner.lean crashed, likely due to a stack overflow or a bug.

Is this a known issue, with known workarounds?

[Scott Morrison]

If it persists after a lake exe cache get!, then it's a bug. :-)

[Scott Morrison]

Very likely it is a corrupted olean. Unfortunately these files are large and prone to corruption during download, and we just blindly memory-map them.

[Sebastian Ullrich]

Files shouldn't just spontaneously get corrupted during downloading. Is the issue that a failed download leaves behind a truncated file (in which case shouldn't tar fail first?)?

[Yury G. Kudryashov]

BTW, should we sign the archives?