Use the same z-stream branch creation logic as rhpkg implementation

ymir/agents/backport_agent.py

@@ -28,6 +28,7 @@
     I_AM_YMIR,
     ZSTREAM_TARGET_LABEL,
     format_jira_links_for_mr,
+    format_zstream_branch_note,
     mr_description_footer,
 )
 from ymir.agents.log_agent import create_log_agent
@@ -665,6 +666,7 @@ async def fork_and_prepare_dist_git(state):
                 state.update_branch,
                 state.fork_url,
                 _,
+                state.zstream_branch_created,
             ) = await tasks.fork_and_prepare_dist_git(
                 jira_issue=state.jira_issue,
                 package=state.package,
@@ -930,7 +932,8 @@ async def evaluate_inherit_source(state):
                     f"{triage_details_text}"
                     f"{format_jira_links_for_mr(state.jira_issue)}\n"
                     f"{wrap_details('Backporting steps', state.backport_log[-1])}"
-                    f"\n\n{mr_description_footer(state.package)}"
+                    f"\n\n{format_zstream_branch_note(state.zstream_branch_created)}"
+                    f"{mr_description_footer(state.package)}"
                 )
                 state.backport_result = BackportOutputSchema(
                     success=True,
@@ -1403,7 +1406,8 @@ async def commit_push_and_open_mr(state):
                     f"{triage_details_text}"
                     f"{format_jira_links_for_mr(state.jira_issue)}\n"
                     f"{wrap_details('Backporting steps', state.backport_log[-1])}"
-                    f"\n\n{mr_description_footer(state.package)}"
+                    f"\n\n{format_zstream_branch_note(state.zstream_branch_created)}"
+                    f"{mr_description_footer(state.package)}"
                 )
                 (
                     state.merge_request_url,

ymir/agents/constants.py

@@ -70,6 +70,12 @@ def strip_resolves_from_mr_text(text: str) -> str:
     return "\n".join(result).strip("\n")
 
 
+def format_zstream_branch_note(note: str | None) -> str:
+    if not note:
+        return ""
+    return f"> **Note:** {note}\n\n"
+
+
 def mr_description_footer(package: str) -> str:
     return (
         "---\n"  # noqa: S608

ymir/agents/mr_consolidation_agent.py

@@ -510,6 +510,7 @@ async def fork_and_prepare_dist_git(state):
                 state.update_branch,
                 state.fork_url,
                 _,
+                _,
             ) = await tasks.fork_and_prepare_dist_git(
                 jira_issue=working_id,
                 package=package,

ymir/agents/package_update_steps.py

@@ -26,6 +26,7 @@ class PackageUpdateState(BaseModel):
     log_result: LogOutputSchema | None = Field(default=None)
     merge_request_url: str | None = Field(default=None)
     merge_request_newly_created: bool = Field(default=False)  # was the MR newly created?
+    zstream_branch_created: str | None = Field(default=None)
 
 
 class PackageUpdateStep:

ymir/agents/rebase_agent.py

@@ -24,6 +24,7 @@
     I_AM_YMIR,
     ZSTREAM_TARGET_LABEL,
     format_jira_links_for_mr,
+    format_zstream_branch_note,
     mr_description_footer,
 )
 from ymir.agents.log_agent import create_log_agent
@@ -354,6 +355,7 @@ async def fork_and_prepare_dist_git(state):
                     state.update_branch,
                     state.fork_url,
                     state.fedora_clone,
+                    state.zstream_branch_created,
                 ) = await tasks.fork_and_prepare_dist_git(
                     jira_issue=state.jira_issue,
                     package=state.package,
@@ -525,7 +527,8 @@ async def commit_push_and_open_mr(state):
                             f"{format_jira_links_for_mr(all_issues)}\n"
                             f"{wrap_details('Rebase status', state.rebase_log[-1])}"
                             f"{consolidation_text}"
-                            f"\n\n{mr_description_footer(state.package)}"
+                            f"\n\n{format_zstream_branch_note(state.zstream_branch_created)}"
+                            f"{mr_description_footer(state.package)}"
                         ),
                         available_tools=gateway_tools,
                         commit_only=dry_run,

ymir/agents/rebuild_agent.py

@@ -14,6 +14,7 @@
     I_AM_YMIR,
     ZSTREAM_TARGET_LABEL,
     format_jira_links_for_mr,
+    format_zstream_branch_note,
     mr_description_footer,
 )
 from ymir.agents.log_agent import create_log_agent
@@ -105,6 +106,7 @@ async def fork_and_prepare_dist_git(state):
                     state.update_branch,
                     state.fork_url,
                     _,
+                    state.zstream_branch_created,
                 ) = await tasks.fork_and_prepare_dist_git(
                     jira_issue=state.jira_issue,
                     package=state.package,
@@ -259,7 +261,8 @@ async def commit_push_and_open_mr(state):
                             f"{side_tag_text}\n"
                             f"{triage_details_text}"
                             f"{consolidation_text}"
-                            f"\n\n{mr_description_footer(state.package)}"
+                            f"\n\n{format_zstream_branch_note(state.zstream_branch_created)}"
+                            f"{mr_description_footer(state.package)}"
                         ),
                         available_tools=gateway_tools,
                         commit_only=dry_run,

ymir/agents/tasks.py

@@ -239,7 +239,7 @@ async def fork_and_prepare_dist_git(
     agent_type: str,
     with_fedora: bool = False,
     dist_git_namespace: str | None = None,
-) -> tuple[Path, str, str, Path | None]:
+) -> tuple[Path, str, str, Path | None, str | None]:
     if not jira_issue or Path(jira_issue).is_absolute() or ".." in jira_issue:
         raise ValueError(f"Invalid jira_issue: {jira_issue}")
     # Scoped by agent_type so different agent types processing the same
@@ -255,13 +255,16 @@ async def fork_and_prepare_dist_git(
     local_clone = working_dir / package
     # create_zstream_branch only applies to plain internal rhel-X.Y[.0] branches;
     # modular stream-* branches already exist in the rhel project.
+    zstream_branch_created = None
     if not is_cs_branch(dist_git_branch) and not is_modular_branch(dist_git_branch):
-        await run_tool(
+        result = await run_tool(
             "create_zstream_branch",
             package=package,
             branch=dist_git_branch,
             available_tools=available_tools,
         )
+        if "already exists" not in result:
+            zstream_branch_created = result
     if await is_older_zstream(dist_git_branch):
         await run_tool(
             "clone_repository",
@@ -286,7 +289,7 @@ async def fork_and_prepare_dist_git(
         fedora_clone = working_dir / f"{package}-fedora"
         if not await _clone_fedora_dist_git(package, fedora_clone):
             fedora_clone = None
-    return local_clone, update_branch, fork_url, fedora_clone
+    return local_clone, update_branch, fork_url, fedora_clone, zstream_branch_created
 
 
 async def find_leading_zstream_branch(dist_git_branch: str) -> str | None:

ymir/tools/privileged/distgit.py

@@ -37,7 +37,6 @@
     "no route to host",
     "broken pipe",
     "ssh_exchange_identification",
-    "failed to push some refs",
 )
 
 _T = TypeVar("_T")
@@ -55,10 +54,11 @@ async def _retry_transient(
     label: str,
     max_retries: int = _TRANSIENT_MAX_RETRIES,
     base_delay: int = _TRANSIENT_BASE_DELAY,
+    retry_on_empty: bool = False,
 ) -> _T:
     for attempt in range(max_retries):
         try:
-            return await fn()
+            result = await fn()
         except Exception as e:
             if attempt < max_retries - 1 and _is_transient_git_error(e):
                 backoff = random.uniform(0, base_delay * 2**attempt)  # noqa: S311
@@ -69,6 +69,16 @@ async def _retry_transient(
                 await asyncio.sleep(backoff)
             else:
                 raise
+        else:
+            if retry_on_empty and not result and attempt < max_retries - 1:
+                backoff = random.uniform(0, base_delay * 2**attempt)  # noqa: S311
+                logger.warning(
+                    f"{label} returned empty (attempt {attempt + 1}/{max_retries}); "
+                    f"retrying in {backoff:.1f}s"
+                )
+                await asyncio.sleep(backoff)
+            else:
+                return result
     raise AssertionError("unreachable")
 
 
@@ -215,6 +225,7 @@ async def _clone():
 
             with tool_error_context("Failed to clone dist-git repo", package=package, clone_url=clone_url):
                 repo = await _retry_transient(_clone, f"clone {package} from dist-git")
+            branch_creation_details = None
             if branch in [ref.name.split("/")[-1] for ref in repo.remotes.origin.refs]:
                 # Branch already exists in dist-git but not yet mirrored to GitLab.
                 # This happens when a previous push succeeded server-side but the SSH
@@ -230,31 +241,47 @@ async def _clone():
                         _, ref = await get_latest_z_pending_build(package, branch)
                     else:
                         _, ref = await get_latest_candidate_build(package, branch)
-                if source_branch := self._find_source_branch(repo, branch):
+                source_branch = self._find_source_branch(repo, branch)
+                if source_branch and source_branch.endswith("-main"):
                     ref = await self._find_latest_same_nvr_ref(
                         repo,
                         package,
                         ref,
                         source_branch,
                     )
+                    branch_creation_details = f"from {source_branch} at {ref[:12]}"
+                else:
+                    branch_creation_details = f"at {ref[:12]}"
                 with tool_error_context(
                     "Failed to push branch to dist-git", package=package, branch=branch, ref=ref
                 ):
-                    push_infos = await _retry_transient(
-                        lambda: asyncio.to_thread(repo.remotes.origin.push, f"{ref}:refs/heads/{branch}"),
+                    try:
+                        await asyncio.to_thread(repo.commit, ref)
+                    except Exception:
+                        raise ToolError(
+                            f"Commit {ref} (from latest Brew build) not found in dist-git clone of {package}"
+                        ) from None
+                    await _retry_transient(
+                        lambda: asyncio.to_thread(repo.git.push, "origin", f"{ref}:refs/heads/{branch}"),
                         f"push {branch} to dist-git",
                     )
-                    if getattr(push_infos, "error", None):
-                        logger.error("git push stderr: %s", sanitize_url(str(push_infos.error)))
-                    for info in push_infos:
-                        if info.flags & git.remote.PushInfo.ERROR:
-                            logger.error("Push to dist-git rejected: %s", info.summary.strip())
-                            raise ToolError("Push to dist-git was rejected")
+                    if not await _retry_transient(
+                        lambda: asyncio.to_thread(repo.git.ls_remote, "--heads", "origin", branch),
+                        f"verify {branch} on dist-git",
+                        retry_on_empty=True,
+                    ):
+                        raise ToolError(
+                            f"Push appeared to succeed but branch {branch} not found "
+                            f"on dist-git — possible silent rejection by server ACL"
+                        )
             start_time = time.monotonic()
             while time.monotonic() - start_time < SYNC_TIMEOUT:
                 try:
                     if await asyncio.to_thread(repo.git.ls_remote, gitlab_repo_url, branch, branches=True):
-                        return StringToolOutput(result=f"Successfully created Z-Stream branch {branch}")
+                        msg = f"Successfully created Z-Stream branch {branch}"
+                        if branch_creation_details:
+                            msg += f" ({branch_creation_details})"
+                        return StringToolOutput(result=msg)
                 except git.exc.GitCommandError as e:
                     if not _is_transient_git_error(e):
                         logger.error(