guix_mirror_bot pushed a commit to branch master
in repository guix.
commit 82f84f5e7fb34cc719ed6ea538a3d1ca7516f23d
Author: Roman Scherer <[email protected]>
AuthorDate: Sat Mar 7 13:10:43 2026 +0100
daemon: Resolve symlinks in /etc/resolv.conf for slirp4netns chroot.
* nix/libstore/build.cc (prepareSlirpChrootAction): Use
canonPath(i, true) to resolve symlinks when adding /etc/resolv.conf
and /etc/hosts to the slirp4netns chroot, so that bindMount receives
a regular file path instead of a symlink.
On systems using systemd-resolved, /etc/resolv.conf is typically a
symlink:
/etc/resolv.conf -> /run/systemd/resolve/stub-resolv.conf
The slirp4netns chroot creates an empty /run/ directory, so when
bindMount copies the symlink verbatim (spawn.cc line 537-542), the
target does not exist and slirp4netns cannot determine the upstream
DNS server. This causes all DNS resolution to fail for fixed-output
derivations that use the Guile-based git-fetch builder (e.g.
git-fetch/lfs), since they rely on slirp4netns for network access
in the build chroot.
Derivations using builtin:git-download are unaffected because they
run in the daemon process itself, which has full network access.
Change-Id: Ib73e69a8760e74eb8141dd0408c27aa8b3001e37
Signed-off-by: Ludovic Courtès <[email protected]>
Merges: #6959
---
nix/libstore/build.cc | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/nix/libstore/build.cc b/nix/libstore/build.cc
index 3071c8ef10..9bdf0a78ae 100644
--- a/nix/libstore/build.cc
+++ b/nix/libstore/build.cc
@@ -1972,11 +1972,15 @@ static void prepareSlirpChrootAction(SpawnContext &
sctx)
}
/* Limit /etc to containing just /etc/resolv.conf and /etc/hosts, and
- read-only at that */
+ read-only at that. Resolve symlinks in the source path so that
+ bindMount sees a regular file and bind-mounts it, rather than
+ copying a symlink whose target may not exist in the chroot
+ (e.g. /etc/resolv.conf -> /run/systemd/resolve/stub-resolv.conf
+ with /run/ being empty in the chroot). */
Strings etcFiles = { "/etc/resolv.conf", "/etc/hosts" };
for(auto & i : etcFiles) {
if(pathExists(i)) {
- ctx.filesInChroot[i] = i;
+ ctx.filesInChroot[i] = canonPath(i, true);
ctx.readOnlyFilesInChroot.insert(i);
}
}
