e2e: 628 不设能力门,拒绝规则与平台无关;记下 diag 的去重是设计属性

Author: speak-agent

src/build/prepare.cppm

@@ -3918,6 +3918,11 @@ prepare_build(bool print_fingerprint,
         // REPORTED, NOT INFERRED. An override that is only visible as "two
         // versions were declared and one directory exists" is a fact the reader
         // has to reconstruct from the filesystem.
+        //
+        // This lambda runs twice per build (the early pass and the late one),
+        // and the reader sees each note ONCE: `mcpp::diag` deduplicates by the
+        // whole payload, which is a designed property rather than an accident
+        // of where these two calls sit.
         for (auto const& note : unified->overrides)
             mcpp::diag::warning("xlings/version-override", note);
         return std::pair{std::move(rootSpecs), std::move(fromGraph)};

tests/e2e/628_a_pin_below_a_stated_floor_is_refused.sh

@@ -1,5 +1,11 @@
 #!/usr/bin/env bash
-# requires: gcc
+# requires:
+# NO CAPABILITY GATE, unlike its two neighbours. They need a dependency's
+# build program to run, and `gcc` is how this runner spells "a toolchain that
+# compiles one"; this test's first leg refuses before anything is compiled and
+# its second only builds an ordinary library. The rule it checks is
+# platform-independent, so it should be checked on every platform -- a Windows
+# runner is where a path or a quoting assumption would surface.
 # A PIN THAT DOES NOT SATISFY A STATED FLOOR IS A REFUSAL, NOT A SECOND INSTALL.
 #
 # Once one package means one version, the two declarations have to be