deb: install build-deps per dpkg cross semantics

Replace the apt-get build-dep passes with a native resolver: the Build-* clauses are evaluated against the context's package state by crate::debian::deps (the dpkg-checkbuilddeps equivalent), and the unsatisfied ones install through explicitly architecture-qualified names. apt's --host-architecture build-dep resolution is coarser than the checker it feeds: unqualified Multi-Arch: same libraries only ever get the host-architecture variant, and there is no way to also satisfy the build-architecture needs of a cross build without a native re-resolution pass — which installs co-install partners that break unpacking for -dev packages whose variants conflict on arch-differing files (curl-config; the libcurl4-gnutls-dev regression). The resolver now applies the same dpkg rules as the checker, preferring the runnable build-architecture variant of Multi-Arch: foreign tools, and passes virtual names through to apt. Build-Conflicts are now checked before anything installs, which the build-dep passes never did, and a failed dose3 diagnosis no longer masks the resolver error (a latent flaw of the passes: binary-only builds have no .dsc for dose-builddebcheck to read). An end-to-end test pins the expected failure: a cross build whose build-dependencies cannot satisfy dpkg's cross semantics aborts, naming the dependency.
2026-09-20 18:04:13 +02:00
parent 02cb5306f3
commit af9845c480
2 changed files with 638 additions and 54 deletions
@@ -739,4 +739,74 @@ mod tests {
            "arch-independant .deb not produced, got: {deb_files:?}"
        );
    }
+
+    /// A cross build whose build-dependencies cannot be satisfied under
+    /// dpkg's cross semantics must abort at the install step, naming the
+    /// unsatisfied dependency: the expected-failure counterpart of the
+    /// cross builds above.
+    #[tokio::test]
+    #[test_log::test]
+    #[cfg(target_arch = "x86_64")]
+    async fn test_deb_cross_unsatisfiable_build_dep_fails_end_to_end() {
+        let temp_dir = tempfile::tempdir().unwrap();
+        let pkg_dir = temp_dir.path().join("pkh-crosstest");
+        std::fs::create_dir_all(pkg_dir.join("debian/source")).unwrap();
+
+        std::fs::write(
+            pkg_dir.join("debian/changelog"),
+            "pkh-crosstest (1.0) noble; urgency=medium\n\n  \
+             * Synthetic package declaring an unsatisfiable build-dependency.\n\n \
+             -- pkh tests <pkh@example.com>  Tue, 15 Sep 2026 08:00:00 +0000\n",
+        )
+        .unwrap();
+
+        std::fs::write(
+            pkg_dir.join("debian/control"),
+            "Source: pkh-crosstest\n\
+             Section: devel\n\
+             Priority: optional\n\
+             Maintainer: pkh tests <pkh@example.com>\n\
+             Standards-Version: 4.7.4\n\
+             Build-Depends: pkh-no-such-package-xyz\n\
+             Architecture: any\n\
+             \n\
+             Package: pkh-crosstest\n\
+             Architecture: any\n\
+             Depends: ${misc:Depends}, ${shlibs:Depends}\n\
+             Description: Cross-build negative regression package\n \
+              Declares a build-dependency absent from the archive.\n",
+        )
+        .unwrap();
+
+        std::fs::write(
+            pkg_dir.join("debian/rules"),
+            "#!/usr/bin/make -f\n%:\n\tdh $@\n",
+        )
+        .unwrap();
+        use std::os::unix::fs::PermissionsExt;
+        let rules = pkg_dir.join("debian/rules");
+        let mut perms = std::fs::metadata(&rules).unwrap().permissions();
+        perms.set_mode(0o755);
+        std::fs::set_permissions(&rules, perms).unwrap();
+
+        std::fs::write(pkg_dir.join("debian/source/format"), "3.0 (native)\n").unwrap();
+
+        let ctx = Arc::new(Context::new(crate::context::ContextConfig::Local).unwrap());
+
+        let err = crate::deb::build_binary_package(DebBuildOptions {
+            arch: Some("arm64".to_string()),
+            series: Some("noble".to_string()),
+            cwd: Some(pkg_dir),
+            cross: true,
+            ctx: Some(ctx),
+            ..Default::default()
+        })
+        .await
+        .expect_err("an unsatisfiable build-dependency must fail the cross build");
+
+        assert!(
+            err.to_string().contains("pkh-no-such-package-xyz"),
+            "error should name the unsatisfied dependency: {err}"
+        );
+    }
 }