meson: Make detection of python more robust

anarazel · anarazel · commit c79ca0485a62 · 2023-10-20T11:11:36.000-07:00
Previously we errored out if no python installation could be found (but we did handle not having enough of python installed to build plpython against). Presumably nobody hit this so far, as python is likely installed due to meson requiring python. Author: Tristan Partin <tristan@neon.tech> Discussion: https://postgr.es/m/CSPIJVUDZFKX.3KHMOAVGF94RV@c3po Backpatch: 16-, where meson support was added
diff --git a/meson.build b/meson.build
@@ -1052,15 +1052,17 @@ endif
 ###############################################################
 
 pyopt = get_option('plpython')
+python3_dep = not_found_dep
 if not pyopt.disabled()
   pm = import('python')
   python3_inst = pm.find_installation(required: pyopt)
-  python3_dep = python3_inst.dependency(embed: true, required: pyopt)
-  if not cc.check_header('Python.h', dependencies: python3_dep, required: pyopt)
-    python3_dep = not_found_dep
+  if python3_inst.found()
+    python3_dep = python3_inst.dependency(embed: true, required: pyopt)
+    # Remove this check after we depend on Meson >= 1.1.0
+    if not cc.check_header('Python.h', dependencies: python3_dep, required: pyopt)
+      python3_dep = not_found_dep
+    endif
   endif
-else
-  python3_dep = not_found_dep
 endif
 
 
