Fix ReuseOtherProjectDefaultTargetRepository architecture

We were choosing the first supported architecture instead of the default
even if a default was explicitly set. This resulted in an error when
building e.g. `libunwind-with-host-compiler` since it tried to set up
LLVM for RISCV64 and therefore checked for a RISCV64 sysroot.

pycheribuild/projects/cmake.py

@@ -61,6 +61,7 @@ class BuildCMake(AutotoolsProject):
     repository = GitRepository("https://github.com/Kitware/CMake",  # a lot faster than "https://cmake.org/cmake.git"
                                # track the stable release branch
                                default_branch="release")
+    default_architecture = CompilationTargets.NATIVE
     native_install_dir = DefaultInstallDir.BOOTSTRAP_TOOLS
     make_kind = MakeCommandKind.Ninja
     add_host_target_build_config_options = False

pycheribuild/projects/repository.py

@@ -127,11 +127,15 @@ def update(self, current_project: "Project", *, src_dir: Path, **kwargs):
 
 class ReuseOtherProjectDefaultTargetRepository(ReuseOtherProjectRepository):
     def __init__(self, source_project: "type[Project]", *, subdirectory=".", do_update=False):
+        xtarget = source_project.default_architecture
+        if xtarget is None and len(source_project.supported_architectures) == 1:
+            xtarget = source_project.supported_architectures[0]
+        assert xtarget is not None
         super().__init__(
             source_project,
             subdirectory=subdirectory,
             do_update=do_update,
-            repo_for_target=source_project.supported_architectures[0],
+            repo_for_target=xtarget,
         )
 
 

tests/test_argument_parsing.py

@@ -1157,8 +1157,8 @@ def test_source_dir_option_when_reusing_git_repo():
     )
     assert str(_get_target_instance("llvm-native", config).source_dir) == "/custom/llvm/dir3"
     assert str(_get_target_instance("compiler-rt-native", config).source_dir) == "/custom/compiler-rt/dir3"
-    # compiler-rt-riscv64 uses the default path, since we only changed llvm-native and compiler-rt-native:
-    assert str(_get_target_instance("compiler-rt-riscv64", config).source_dir) == "/foo/llvm-project/compiler-rt"
+    # compiler-rt-riscv64 uses the default path (llvm-native source), since we only changed compiler-rt-native:
+    assert str(_get_target_instance("compiler-rt-riscv64", config).source_dir) == "/custom/llvm/dir3/compiler-rt"
 
     # Check that cheribsd-mfs-root-kernel reused the cheribsd source dir
     assert str(_get_target_instance("cheribsd-mfs-root-kernel-riscv64-purecap", config).source_dir) == "/foo/cheribsd"