Merge pull request #11922 from picnoir/pic/catch-gc-exception

gc: resume GC after a pathinuse error

src/libstore/gc.cc

@@ -4,6 +4,7 @@
 #include "finally.hh"
 #include "unix-domain-socket.hh"
 #include "signals.hh"
+#include "posix-fs-canonicalise.hh"
 
 #if !defined(__linux__)
 // For shelling out to lsof
@@ -763,13 +764,18 @@ void LocalStore::collectGarbage(const GCOptions & options, GCResults & results)
                 }
             }
         }
-
         for (auto & path : topoSortPaths(visited)) {
             if (!dead.insert(path).second) continue;
             if (shouldDelete) {
+                try {
                     invalidatePathChecked(path);
                     deleteFromStore(path.to_string());
                     referrersCache.erase(path);
+                } catch (PathInUse &e) {
+                    // If we end up here, it's likely a new occurence
+                    // of https://github.com/NixOS/nix/issues/11923
+                    printError("BUG: %s", e.what());
+                }
             }
         }
     };