GitExportIgnoreSourceAccessor: Don't show «unknown»

In general we should set the path display prefix on the inner
accessor, so we now pass the display prefix to getAccessor().

(cherry picked from commit 3032512425)

src/libfetchers/git-utils.cc

@@ -508,7 +508,10 @@ struct GitRepoImpl : GitRepo, std::enable_shared_from_this<GitRepoImpl>
      */
     ref<GitSourceAccessor> getRawAccessor(const Hash & rev);
 
-    ref<SourceAccessor> getAccessor(const Hash & rev, bool exportIgnore) override;
+    ref<SourceAccessor> getAccessor(
+        const Hash & rev,
+        bool exportIgnore,
+        std::string displayPrefix) override;
 
     ref<SourceAccessor> getAccessor(const WorkdirInfo & wd, bool exportIgnore, MakeNotAllowedError e) override;
 
@@ -627,7 +630,7 @@ struct GitRepoImpl : GitRepo, std::enable_shared_from_this<GitRepoImpl>
 
     Hash treeHashToNarHash(const Hash & treeHash) override
     {
-        auto accessor = getAccessor(treeHash, false);
+        auto accessor = getAccessor(treeHash, false, "");
 
         fetchers::Cache::Key cacheKey{"treeHashToNarHash", {{"treeHash", treeHash.gitRev()}}};
 
@@ -1194,17 +1197,19 @@ ref<GitSourceAccessor> GitRepoImpl::getRawAccessor(const Hash & rev)
     return make_ref<GitSourceAccessor>(self, rev);
 }
 
-ref<SourceAccessor> GitRepoImpl::getAccessor(const Hash & rev, bool exportIgnore)
+ref<SourceAccessor> GitRepoImpl::getAccessor(
+    const Hash & rev,
+    bool exportIgnore,
+    std::string displayPrefix)
 {
     auto self = ref<GitRepoImpl>(shared_from_this());
     ref<GitSourceAccessor> rawGitAccessor = getRawAccessor(rev);
-    if (exportIgnore) {
+    rawGitAccessor->setPathDisplay(std::move(displayPrefix));
+    if (exportIgnore)
         return make_ref<GitExportIgnoreSourceAccessor>(self, rawGitAccessor, rev);
-    }
+    else
-    else {
         return rawGitAccessor;
 }
-}
 
 ref<SourceAccessor> GitRepoImpl::getAccessor(const WorkdirInfo & wd, bool exportIgnore, MakeNotAllowedError makeNotAllowedError)
 {
@@ -1236,7 +1241,7 @@ std::vector<std::tuple<GitRepoImpl::Submodule, Hash>> GitRepoImpl::getSubmodules
     /* Read the .gitmodules files from this revision. */
     CanonPath modulesFile(".gitmodules");
 
-    auto accessor = getAccessor(rev, exportIgnore);
+    auto accessor = getAccessor(rev, exportIgnore, "");
     if (!accessor->pathExists(modulesFile)) return {};
 
     /* Parse it and get the revision of each submodule. */

src/libfetchers/git-utils.hh

@@ -86,7 +86,10 @@ struct GitRepo
 
     virtual bool hasObject(const Hash & oid) = 0;
 
-    virtual ref<SourceAccessor> getAccessor(const Hash & rev, bool exportIgnore) = 0;
+    virtual ref<SourceAccessor> getAccessor(
+        const Hash & rev,
+        bool exportIgnore,
+        std::string displayPrefix) = 0;
 
     virtual ref<SourceAccessor> getAccessor(const WorkdirInfo & wd, bool exportIgnore, MakeNotAllowedError makeNotAllowedError) = 0;
 

src/libfetchers/git.cc

@@ -672,9 +672,7 @@ struct GitInputScheme : InputScheme
         verifyCommit(input, repo);
 
         bool exportIgnore = getExportIgnoreAttr(input);
-        auto accessor = repo->getAccessor(rev, exportIgnore);
+        auto accessor = repo->getAccessor(rev, exportIgnore, "«" + input.to_string() + "»");
-
-        accessor->setPathDisplay("«" + input.to_string() + "»");
 
         /* If the repo has submodules, fetch them and return a mounted
            input accessor consisting of the accessor for the top-level

src/libfetchers/github.cc

@@ -294,9 +294,10 @@ struct GitArchiveInputScheme : InputScheme
         #endif
         input.attrs.insert_or_assign("lastModified", uint64_t(tarballInfo.lastModified));
 
-        auto accessor = getTarballCache()->getAccessor(tarballInfo.treeHash, false);
+        auto accessor = getTarballCache()->getAccessor(
-
+            tarballInfo.treeHash,
-        accessor->setPathDisplay("«" + input.to_string() + "»");
+            false,
+            "«" + input.to_string() + "»");
 
         return {accessor, input};
     }

src/libfetchers/tarball.cc

@@ -105,7 +105,8 @@ DownloadFileResult downloadFile(
 
 static DownloadTarballResult downloadTarball_(
     const std::string & url,
-    const Headers & headers)
+    const Headers & headers,
+    const std::string & displayPrefix)
 {
     Cache::Key cacheKey{"tarball", {{"url", url}}};
 
@@ -118,7 +119,7 @@ static DownloadTarballResult downloadTarball_(
             .treeHash = treeHash,
             .lastModified = (time_t) getIntAttr(infoAttrs, "lastModified"),
             .immutableUrl = maybeGetStrAttr(infoAttrs, "immutableUrl"),
-            .accessor = getTarballCache()->getAccessor(treeHash, false),
+            .accessor = getTarballCache()->getAccessor(treeHash, false, displayPrefix),
         };
     };
 
@@ -371,9 +372,10 @@ struct TarballInputScheme : CurlInputScheme
     {
         auto input(_input);
 
-        auto result = downloadTarball_(getStrAttr(input.attrs, "url"), {});
+        auto result = downloadTarball_(
-
+            getStrAttr(input.attrs, "url"),
-        result.accessor->setPathDisplay("«" + input.to_string() + "»");
+            {},
+            "«" + input.to_string() + "»");
 
         if (result.immutableUrl) {
             auto immutableInput = Input::fromURL(*input.settings, *result.immutableUrl);