diff --git a/src/libstore/unix/build/local-derivation-goal.cc b/src/libstore/unix/build/local-derivation-goal.cc index d07315626..48934fc87 100644 --- a/src/libstore/unix/build/local-derivation-goal.cc +++ b/src/libstore/unix/build/local-derivation-goal.cc @@ -2149,7 +2149,18 @@ void LocalDerivationGoal::runChild() without file-write* allowed, access() incorrectly returns EPERM */ sandboxProfile += "(allow file-read* file-write* process-exec\n"; + + // We create multiple allow lists, to avoid exceeding a limit in the darwin sandbox interpreter. + // See https://github.com/NixOS/nix/issues/4119 + // We split our allow groups approximately at half the actual limit, 1 << 16 + const int breakpoint = sandboxProfile.length() + (1 << 14); for (auto & i : pathsInChroot) { + + if (sandboxProfile.length() >= breakpoint) { + debug("Sandbox break: %d %d", sandboxProfile.length(), breakpoint); + sandboxProfile += ")\n(allow file-read* file-write* process-exec\n"; + } + if (i.first != i.second.source) throw Error( "can't map '%1%' to '%2%': mismatched impure paths not supported on Darwin",