Merge ~racb/git-ubuntu:rich-history-auth into git-ubuntu:main

[Robie Basak]

Make Jenkins happy

[Server Team CI bot (server-team-bot)]

PASSED: Continuous integration, rev:820afcd1e0d2db9e431cbbfe6c8b5a91173419c1
https://jenkins.canonical.com/server-team/job/git-ubuntu-ci/33/
Executed test runs:
    SUCCESS: VM Setup
    SUCCESS: Build
    SUCCESS: VM Reset
    SUCCESS: Unit Tests
    IN_PROGRESS: Declarative: Post Actions

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review: Approve (continuous-integration)

[Lena Voytek (lvoytek)]

LGTM, just found one comment that could use some slight rewording. Thanks for adding this!

review: Approve

[Robie Basak (racb)]

Fixed, thanks!

diff --git a/gitubuntu/importer.py b/gitubuntu/importer.py
index ebd88af..a50c3e6 100644
--- a/gitubuntu/importer.py
+++ b/gitubuntu/importer.py
@@ -102,6 +102,12 @@ VCS_GIT_COMMIT_VALIDATION = re.compile(r'[A-Za-z0-9]{40}')
 # must be called with LC_ALL="C.UTF-8".
 GIT_REMOTE_REF_MISSING_PREFIX = b"fatal: couldn't find remote ref"
 
+# These are the first bytes in stderr from git if "git fetch" is called and
+# prompts for authentication but we have disabled that with
+# GIT_TERMINAL_PROMPT=0. This seems like the least worst method of detecting
+# this case to turn it into a RichHistoryNotFound exception.
+GIT_REMOTE_AUTH_FAILED_PREFIX = b"fatal: could not read Username "
+
 
 class GitUbuntuImportError(Exception):
     pass
@@ -1951,8 +1957,12 @@ def fetch_rich_history_from_changes_file(
                     repo.git_run(
                         ['fetch', rich_url, rich_ref],
                         # Since we parse the output, we must make sure the
-                        # output will contain untranslated strings
-                        env={'LC_ALL': 'C.UTF-8'},
+                        # output will contain untranslated strings. If this
+                        # prompts for auth, then we can just treat it as a
+                        # failure, and it's generally wrong for Vcs-Git to
+                        # require auth anyway, so we should just suppress the
+                        # prompt (LP: #1980982).
+                        env={'LC_ALL': 'C.UTF-8', 'GIT_TERMINAL_PROMPT': '0'},
                     )
                 except CalledProcessError as e:
                     if (
@@ -1960,6 +1970,11 @@ def fetch_rich_history_from_changes_file(
                         e.stderr.startswith(GIT_REMOTE_REF_MISSING_PREFIX)
                     ):
                         raise RichHistoryNotFoundError() from e
+                    elif (
+                        e.stderr and
+                        e.stderr.startswith(GIT_REMOTE_AUTH_FAILED_PREFIX)
+                    ):
+                        raise RichHistoryNotFoundError() from e
                     else:
                         raise
     except tenacity.RetryError as e: