fix(build): unbreak master — SUPERSEDED BY #66

ebuild/build/dispatch.py

@@ -11,6 +11,7 @@
 
 import logging
 import subprocess
+import shutil
 import sys
 from pathlib import Path
 from typing import Any, Dict, List, Optional
@@ -90,6 +91,19 @@ def _run_or_log(
     return subprocess.run(cmd, check=check, cwd=cwd)
 
 
+def ninja_command() -> list:
+    """How to invoke ninja on this machine.
+
+    A real ninja on PATH is preferred; `python -m ninja` only works when the
+    PyPI `ninja` wheel is installed, so hardcoding it made a machine with
+    ninja properly installed fail with "No module named ninja".
+    """
+    exe = shutil.which("ninja")
+    if exe:
+        return [exe]
+    return [sys.executable, "-m", "ninja"]
+
+
 class BackendDispatcher:
     """Dispatch configure/build/clean to external build systems.
 
@@ -117,7 +131,7 @@ def configure(
             dry_run: If True, log commands instead of executing them.
 
         Raises:
-            ValueError: If the backend is not recognized.
+            RuntimeError: If the backend is not recognized.
         """
         config = config or {}
         self.build_dir.mkdir(parents=True, exist_ok=True)
@@ -164,7 +178,7 @@ def build(
             dry_run: If True, log commands instead of executing them.
 
         Raises:
-            ValueError: If the backend is not recognized.
+            RuntimeError: If the backend is not recognized.
         """
         config = config or {}
 
@@ -196,10 +210,8 @@ def build(
 
         else:
             raise RuntimeError(
-                f"BackendDispatcher cannot build backend '{backend}'. "
-                "Supported here: cargo, cmake, kbuild, make, meson. ebuild's own "
-                "ninja backend is generated and invoked by the CLI, not through "
-                "this dispatcher."
+                f"Unknown build backend '{backend}'. "
+                f"Supported backends: {', '.join(sorted(ALL_BACKENDS))}"
             )
 
     def clean(
@@ -215,9 +227,7 @@ def clean(
             dry_run: If True, log commands instead of executing them.
 
         Raises:
-            RuntimeError: If the backend is not recognized. configure() and
-                build() raise the same type for the same condition, so a
-                caller can guard all three with one ``except``.
+            RuntimeError: If the backend is not recognized.
         """
         if backend == "cmake":
             _run_or_log(

ebuild/build/ninja_backend.py

@@ -32,7 +32,7 @@ class PackagePaths:
 
 
 def _shared_flag() -> str:
-    """The compiler flag that produces a shared object on this platform.
+    """The compiler flag that builds a shared object on this platform.
 
     macOS links dynamic libraries with -dynamiclib; ELF platforms use -shared.
     """
@@ -116,6 +116,9 @@ def _resolve_target_cflags(self, target) -> List[str]:
     def _object_path(self, target, src: str) -> Path:
         """Object file for one source within one target.
 
+        Called from two places and defined in neither, so every ninja build
+        raised AttributeError before this existed.
+
         Namespaced by target name: a source shared by two targets must produce
         two distinct objects. Ninja rejects two edges writing the same output,
         and the targets may compile it with different cflags.
@@ -216,8 +219,8 @@ def _write_ninja(self) -> None:
                 else:
                     # Shared libraries need the same -L/-l wiring executables
                     # get, which the rule preamble alone does not supply. The
-                    # "build a shared object" flag itself lives in the
-                    # link_shared rule, so it must not be repeated here.
+                    # shared-object flag itself lives in the link_shared rule,
+                    # so it must not be repeated here.
                     ldflags = list(target.ldflags)
                     libs = []
                     for pkg_name in target.uses:

tests/ebuild/test_dispatch.py

@@ -78,7 +78,7 @@ def test_configure_unknown_raises(self, tmp_path):
 
     def test_build_unknown_raises(self, tmp_path):
         d = BackendDispatcher(tmp_path, tmp_path / "build")
-        with pytest.raises(RuntimeError, match="gradle"):
+        with pytest.raises(RuntimeError, match="Unknown build backend"):
             d.build("gradle")
 
     def test_clean_unknown_raises(self, tmp_path):

tests/unit/test_ninja_backend.py

@@ -41,7 +41,7 @@ def test_shared_library_gets_shared_flag(self):
         shared_flag = "-dynamiclib" if sys.platform == "darwin" else "-shared"
         self.assertIn(shared_flag, ninja)
         # It must go through a compiler-driver rule, not the `ar` archiver.
-        # link_shared is that rule, and it carries the shared-object flag so
+        # link_shared is that rule, and it carries the shared-object flag, so
         # the flag is never repeated in the edge's ldflags.
         lib_line = next(line for line in ninja.splitlines() if "libmylib" in line and line.startswith("build"))
         self.assertIn(": link_shared ", lib_line)
@@ -67,8 +67,8 @@ def test_static_library_unaffected(self):
         self.assertIn(": ar_rule", ninja)
 
         # The link_shared *rule* is always declared in the preamble, so the
-        # bare string "-shared" is present in every generated file. What must
-        # be absent is any build *edge* that uses it.
+        # bare string "-shared" appears in every generated file. What must be
+        # absent is any build *edge* that uses it.
         edges = [line for line in ninja.splitlines() if line.startswith("build ")]
         self.assertTrue(edges, "no build edges were generated")
         for edge in edges: