From 3ec287413828cea4e9a8604a0066566539b74b70 Mon Sep 17 00:00:00 2001
From: Nando Vieira <me@fnando.com>
Date: Thu, 18 Jun 2026 11:06:59 -0700
Subject: [PATCH] Resolve alias target for releases on older distros.

---
 scripts/lib/builds.py      | 17 ++++++++++++-----
 scripts/publish_aliases.py |  6 ++++--
 tests/unit/test_builds.py  | 33 ++++++++++++++++++++++++++++++---
 3 files changed, 46 insertions(+), 10 deletions(-)

diff --git a/scripts/lib/builds.py b/scripts/lib/builds.py
index 3d169a6..a0167bd 100644
--- a/scripts/lib/builds.py
+++ b/scripts/lib/builds.py
@@ -89,16 +89,23 @@ def derive_default_rust(data: dict[str, Any], cli: str) -> str:
     entry = find_cli(data, cli)
     if entry is None:
         raise ValueError(f"unknown stellar-cli version: {cli}")
+    pins = entry.get("rust_versions", [])
+    if not pins:
+        raise ValueError(f"stellar-cli {cli} declares no rust_versions[] pins")
     matches = [
         (semver.parse(rust_keys.version_of(label_of(pin))), idx, pin)
-        for idx, pin in enumerate(entry.get("rust_versions", []))
+        for idx, pin in enumerate(pins)
         if label_of(pin).endswith(f"-{suffix}")
     ]
     if not matches:
-        raise ValueError(
-            f"no rust_versions[] pin matches default_distro {distro!r} "
-            f"(suffix {suffix!r}) for stellar-cli {cli}"
-        )
+        # A release predating the current default_distro (e.g. a bookworm-only
+        # back-port published after the repo switched to trixie) has no pin
+        # matching the default suffix. Fall back to the release's own pins so
+        # its `:<cli>` alias still resolves, instead of failing the publish.
+        matches = [
+            (semver.parse(rust_keys.version_of(label_of(pin))), idx, pin)
+            for idx, pin in enumerate(pins)
+        ]
     # Highest rust version wins; among equal versions (a relabelled base), the
     # last-appended pin — the freshest digest — wins.
     matches.sort(key=lambda t: (t[0], t[1]))
diff --git a/scripts/publish_aliases.py b/scripts/publish_aliases.py
index 2bc357e..3d7c968 100755
--- a/scripts/publish_aliases.py
+++ b/scripts/publish_aliases.py
@@ -2,8 +2,10 @@
 """Re-point the `:<cli>` (and `:latest` if newest) tags at the default rust pair.
 
 The default rust pair is the highest-version rust_versions[] key whose
-suffix matches `slim-<default_distro>`. `:latest` is re-pointed only if
-this cli is the newest declared one in builds.json.
+suffix matches `slim-<default_distro>`; a release predating the current
+default_distro (no matching suffix) falls back to its own highest pin.
+`:latest` is re-pointed only if this cli is the newest declared one in
+builds.json.
 """
 
 import argparse
diff --git a/tests/unit/test_builds.py b/tests/unit/test_builds.py
index eff3654..faa0766 100644
--- a/tests/unit/test_builds.py
+++ b/tests/unit/test_builds.py
@@ -126,10 +126,37 @@ def test_derive_default_rust_newest_digest_for_repeated_label() -> None:
     assert builds.derive_default_rust(data, "26.0.0") == newest
 
 
-def test_derive_default_rust_skips_non_matching_suffix(multi_cli_builds: dict) -> None:
-    # 25.1.0 has only bookworm; default_distro is trixie → no match.
+def test_derive_default_rust_falls_back_when_no_suffix_match(multi_cli_builds: dict) -> None:
+    # 25.1.0 has only bookworm; default_distro is trixie → no suffix match,
+    # so it falls back to the release's own highest pin instead of failing.
+    pin = builds.derive_default_rust(multi_cli_builds, "25.1.0")
+    assert builds.label_of(pin).endswith("-slim-bookworm")
+
+
+def test_derive_default_rust_fallback_picks_highest_version() -> None:
+    # Fallback still honours highest-version-wins across mixed non-default pins.
+    older = "1.89.0-slim-bookworm@sha256:" + "a" * 64
+    newer = "1.90.0-slim-bookworm@sha256:" + "b" * 64
+    data = {
+        "default_distro": "trixie",
+        "stellar_cli_versions": [
+            {
+                "ref": "a" * 40,
+                "version": "25.1.0",
+                "rust_versions": [older, newer],
+            }
+        ],
+    }
+    assert builds.derive_default_rust(data, "25.1.0") == newer
+
+
+def test_derive_default_rust_no_pins(multi_cli_builds: dict) -> None:
+    data = {
+        "default_distro": "trixie",
+        "stellar_cli_versions": [{"ref": "a" * 40, "version": "25.1.0", "rust_versions": []}],
+    }
     with pytest.raises(ValueError, match="no rust_versions"):
-        builds.derive_default_rust(multi_cli_builds, "25.1.0")
+        builds.derive_default_rust(data, "25.1.0")
 
 
 def test_derive_default_rust_missing_default_distro(multi_cli_builds: dict) -> None: