Use WAL mode for SQLite cache databases (2nd attempt)#167
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This reverts commit 2b676c6.
This avoids problems with older versions of Nix that don't put the caches in WAL mode. That's generally not a problem, until you do something like nix build --print-out-paths ... | cachix which deadlocks because cachix tries to switch the caches to truncate mode, which requires exclusive access. But the first process cannot make progress because the cachix process isn't reading from the pipe.
colemickens
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Aug 7, 2025
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I've been running this for a bit, seems to be working fine.
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Motivation
See #150, which was reverted in #155.
This time, we update the versions of the SQLite caches. This avoids problems with older versions of Nix that don't put the caches in WAL mode. That's generally not a problem, until you do something like
which deadlocks because cachix tries to switch the caches to truncate mode, which requires exclusive access. But the first process cannot make progress because the cachix process isn't reading from the pipe.
Context