Fix submodules

Author: edolstra

src/libfetchers/git-utils.cc

@@ -740,7 +740,7 @@ ref<GitRepo> GitRepo::openRepo(const std::filesystem::path & path, bool create,
 
 std::string GitAccessorOptions::makeFingerprint(const Hash & rev) const
 {
-    return rev.gitRev() + (exportIgnore ? ";e" : "") + (smudgeLfs ? ";l" : "") + (submodules ? ";s" : "");
+    return rev.gitRev() + (exportIgnore ? ";e" : "") + (smudgeLfs ? ";l" : "");
 }
 
 /**

src/libfetchers/git.cc

@@ -908,8 +908,10 @@ struct GitInputScheme : InputScheme
             }
 
             if (!mounts.empty()) {
+                auto newFingerprint = accessor->getFingerprint(CanonPath::root).second->append(";s");
                 mounts.insert_or_assign(CanonPath::root, accessor);
                 accessor = makeMountedSourceAccessor(std::move(mounts));
+                accessor->fingerprint = newFingerprint;
             }
         }