just-mr: Shell out to system Git for fetches over SSH...

...due to limited SSH support in libgit2. In order to allow the
fetches to still be parallel, we execute:

	git fetch --no-auto-gc --no-write-fetch-head <repo> [<branch>]

This only fetches the packs without updating any refs, at the slight
cost of sometimes fetching some redundant information, which for our
purposes is practically a non-issue.

(If really needed, a 'git gc' call can be done eventually to try to
compact the fetched packs, although a save in disk space is not
actually guaranteed.)

1 files changed, 11 insertions, 6 deletions

diff --git a/src/other_tools/root_maps/commit_git_map.cpp b/src/other_tools/root_maps/commit_git_map.cpp
index fae205ed..3500245b 100644
--- a/src/other_tools/root_maps/commit_git_map.cpp
+++ b/src/other_tools/root_maps/commit_git_map.cpp
@@ -36,6 +36,7 @@ void EnsureCommit(GitRepoInfo const& repo_info,
                   std::filesystem::path const& repo_root,
                   GitCASPtr const& git_cas,
                   gsl::not_null<CriticalGitOpMap*> const& critical_git_op_map,
+                  std::vector<std::string> const& launcher,
                   gsl::not_null<TaskSystem*> const& ts,
                   CommitGitMap::SetterPtr const& ws_setter,
                   CommitGitMap::LoggerPtr const& logger) {
@@ -76,6 +77,7 @@ void EnsureCommit(GitRepoInfo const& repo_info,
         if (not git_repo->FetchViaTmpRepo(tmp_dir->GetPath(),
                                           repo_info.repo_url,
                                           repo_info.branch,
+                                          launcher,
                                           wrapped_logger)) {
             return;
         }
@@ -184,12 +186,14 @@ void EnsureCommit(GitRepoInfo const& repo_info,
 auto CreateCommitGitMap(
     gsl::not_null<CriticalGitOpMap*> const& critical_git_op_map,
     JustMR::PathsPtr const& just_mr_paths,
+    std::vector<std::string> const& launcher,
     std::size_t jobs) -> CommitGitMap {
-    auto commit_to_git = [critical_git_op_map, just_mr_paths](auto ts,
-                                                              auto setter,
-                                                              auto logger,
-                                                              auto /* unused */,
-                                                              auto const& key) {
+    auto commit_to_git = [critical_git_op_map, just_mr_paths, launcher](
+                             auto ts,
+                             auto setter,
+                             auto logger,
+                             auto /* unused */,
+                             auto const& key) {
         // get root for repo (making sure that if repo is a path, it is
         // absolute)
         std::string fetch_repo = key.repo_url;
@@ -213,7 +217,7 @@ auto CreateCommitGitMap(
         critical_git_op_map->ConsumeAfterKeysReady(
             ts,
             {std::move(op_key)},
-            [key, repo_root, critical_git_op_map, ts, setter, logger](
+            [key, repo_root, critical_git_op_map, launcher, ts, setter, logger](
                 auto const& values) {
                 GitOpValue op_result = *values[0];
                 // check flag
@@ -236,6 +240,7 @@ auto CreateCommitGitMap(
                              repo_root,
                              op_result.git_cas,
                              critical_git_op_map,
+                             launcher,
                              ts,
                              setter,
                              wrapped_logger);