Increase the open file soft limit to the hard limit#15205
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On some platforms (macOS), the default soft limit is very low, but the hard limit is high. So let's just raise it the maximum permitted.
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This may be a Determinate Nix specific issue because it's keeping the tarball cache open in Regardless, it probably doesn't hurt to bump the open file limit since there have been various bug reports about this in the past (#8684, #10158). (Though this PR only helps if the hard limit is higher than the soft limit.) |
xokdvium
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Feb 11, 2026
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Good enough for now, but the libgit2 issue should probably get addressed at the root cause. It doesn't seem to close any file descriptors for .pack or .idx files from me strace-ing things.
brittonr
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Increase the open file soft limit to the hard limit
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friedenberg
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- clean-nix-fetcher-cache: interactive wipe of tarball-cache-v2/, tarball-cache/, gitv3/, and fetcher-cache-v4.sqlite*. Refuses to run if any nix processes are alive. Excluded from the aggregate `clean` recipe. - build-nix: split into [linux] (wrapped with prlimit --nofile=1023:1023) and [macos] (unchanged) variants to dodge the upstream nix FD_SETSIZE crash exposed by 2.34.6's RLIMIT_NOFILE bump (NixOS/nix#15205). The select->poll fix (NixOS/nix#15757) is on master only as of 2026-05. - build-home (linux): wrap the `nix run home-manager` invocation with the same prlimit guard. - debug-nix-env-isolation: probe whether env is the differentiator for a `nix build` "missing object" failure that reproduces in one shell but not another. Runs the build under current / minimal / from-file envs and writes each log to .tmp/debug-nix-env-isolation/<ts>/. Tracking issue: #79. :clown: Generated with [Clown](https://github.com/amarbel-llc/clown)
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Motivation
On some platforms (macOS), the default soft limit is very low, but the hard limit is high. So let's just raise it the maximum permitted.
macOS users reported that the tarball cache was failing with errors like
It's possible this started happening because of the multithreaded tarball cache import opening more files in parallel. Hopefully this fixes it.
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