Merge pull request #78 from TheTripleV/pkg

Only load packages that are dependencies

Author: virtuald

robotpy_build/pkgcfg_provider.py

@@ -117,13 +117,35 @@ class PkgCfgProvider:
 
     def __init__(self):
         self.pkgs = {}
-        for entry_point in iter_entry_points(group="robotpybuild", name=None):
-            try:
-                pkg = PkgCfg(entry_point)
-            except Exception as e:
-                warnings.warn(f"Error loading entry point {entry_point.name}: {e}")
-            else:
-                self.add_pkg(pkg)
+
+    def detect_pkgs(self) -> None:
+        """
+            Detect and load packages under the robotpybuild entry point group.
+            Only loads packages that are dependencies.
+        """
+        deps_names = set().union(*[pkg.depends for pkg in self.pkgs.values()])
+        entry_points = list(iter_entry_points(group="robotpybuild", name=None))
+
+        # Only load the dependencies of the package we're building.
+        # If we load the [package being built], then the current build will fail.
+        # If we load a package that depends on the [package being built],
+        # then the [package being built] will be loaded and the current build will fail.
+        run_loop = True
+        while run_loop:
+            run_loop = False
+            for ep in entry_points:
+                if ep.name in self.pkgs:  # Prevents loading the package being built
+                    continue
+                if ep.name not in deps_names and ep.name != "robotpy-build":
+                    continue
+                try:
+                    pkg = PkgCfg(ep)
+                except Exception as e:
+                    warnings.warn(f"Error loading entry point {ep.name}: {e}")
+                else:
+                    self.add_pkg(pkg)
+                    deps_names |= set(pkg.depends)
+                    run_loop = True
 
     def add_pkg(self, pkg: PkgCfg) -> None:
         self.pkgs[pkg.name] = pkg

robotpy_build/setup.py

@@ -105,6 +105,8 @@ def prepare(self):
         self._collect_static_libs()
         self._collect_wrappers()
 
+        self.pkgcfg.detect_pkgs()
+
         self.setup_kwargs["cmdclass"] = {
             "build_py": BuildPy,
             "build_dl": BuildDl,