Fall back to copyPath if link fails with EPERM

BeeGFS doesn't allow hard-links and returns EPERM, so we fall back
to copyPath. See https://github.com/NixOS/nix/issues/3748

1 files changed, 5 insertions, 2 deletions

diff --git a/src/libstore/build.cc b/src/libstore/build.cc
index 0c25897f8..9ac5fd923 100644
--- a/src/libstore/build.cc
+++ b/src/libstore/build.cc
@@ -1950,8 +1950,11 @@ void linkOrCopy(const Path & from, const Path & to)
         /* Hard-linking fails if we exceed the maximum link count on a
            file (e.g. 32000 of ext3), which is quite possible after a
            'nix-store --optimise'. FIXME: actually, why don't we just
-           bind-mount in this case? */
-        if (errno != EMLINK)
+           bind-mount in this case?
+           
+           It can also fail with EPERM in BeegFS v7 and earlier versions
+           which don't allow hard-links to other directories */
+        if (errno != EMLINK && errno != EPERM)
             throw SysError("linking '%s' to '%s'", to, from);
         copyPath(from, to);
     }