Split auto UID allocation from cgroups

Cgroups are now only used for derivations that require the uid-range
range feature. This allows auto UID allocation even on systems that
don't have cgroups (like macOS).

Also, make things work on modern systems that use cgroups v2 (where
there is a single hierarchy and no "systemd" controller).

1 files changed, 2 insertions, 5 deletions

diff --git a/src/libstore/build/local-derivation-goal.hh b/src/libstore/build/local-derivation-goal.hh
index e6700a383..61b0f9145 100644
--- a/src/libstore/build/local-derivation-goal.hh
+++ b/src/libstore/build/local-derivation-goal.hh
@@ -41,9 +41,6 @@ struct LocalDerivationGoal : public DerivationGoal
 
     Path chrootRootDir;
 
-    /* Whether to give the build more than 1 UID. */
-    bool useUidRange = false;
-
     /* Whether to make the 'systemd' cgroup controller available to
        the build. */
     bool useSystemdCgroup = false;
@@ -99,8 +96,8 @@ struct LocalDerivationGoal : public DerivationGoal
        result. */
     std::map<Path, ValidPathInfo> prevInfos;
 
-    uid_t sandboxUid() { return usingUserNamespace ? (useUidRange ? 0 : 1000) : buildUser->getUID(); }
-    gid_t sandboxGid() { return usingUserNamespace ? (useUidRange ? 0 : 100)  : buildUser->getGID(); }
+    uid_t sandboxUid() { return usingUserNamespace ? (buildUser->getUIDCount() == 1 ? 1000 : 0) : buildUser->getUID(); }
+    gid_t sandboxGid() { return usingUserNamespace ? (buildUser->getUIDCount() == 1 ? 100  : 0) : buildUser->getGID(); }
 
     const static Path homeDir;