Fix upstream QEMU build from a venv

This code should have been added to the base class not just the CHERI one.

Author: arichardson

pycheribuild/projects/build_qemu.py

@@ -315,6 +315,25 @@ def setup(self):
                 "--make=" + self.make_args.command,
             ],
         )
+        python_bin = sys.executable
+        python_search_path = self.config.dollar_path_with_other_tools
+        # Python from a venv cannot be used for QEMU builds, use the base installation instead.
+        if sys.prefix != sys.base_prefix:
+            python_bin = sys.executable.replace(sys.prefix, sys.base_prefix)
+            python_search_path = python_search_path.replace(sys.prefix, sys.base_prefix)
+        py3_version = get_program_version(
+            Path(python_bin),
+            config=self.config,
+            regex=re.compile(rb"Python\s+(\d+)\.(\d+)\.?(\d+)?"),
+        )
+        # QEMU tests are not compatible with 3.12 yet, try to use an older version in that case
+        if py3_version >= (3, 12, 0):
+            for minor_version in (11, 10, 9):
+                found = shutil.which(f"python3.{minor_version}", path=python_search_path)
+                if found:
+                    python_bin = found
+                    break
+        self.configure_args.append(f"--python={python_bin}")
 
         if self.config.create_compilation_db:
             self.make_args.set(V=1)  # Otherwise bear can't parse the compiler output
@@ -505,25 +524,6 @@ def setup(self):
         # Linux/BSD-user is not supported for CHERI (yet)
         self.configure_args.append("--disable-bsd-user")
         self.configure_args.append("--disable-linux-user")
-        python_bin = sys.executable
-        python_search_path = self.config.dollar_path_with_other_tools
-        # Python from a venv cannot be used for QEMU builds, use the base installation instead.
-        if sys.prefix != sys.base_prefix:
-            python_bin = sys.executable.replace(sys.prefix, sys.base_prefix)
-            python_search_path = python_search_path.replace(sys.prefix, sys.base_prefix)
-        py3_version = get_program_version(
-            Path(python_bin),
-            config=self.config,
-            regex=re.compile(rb"Python\s+(\d+)\.(\d+)\.?(\d+)?"),
-        )
-        # QEMU tests are not compatible with 3.12 yet, try to use an older version in that case
-        if py3_version >= (3, 12, 0):
-            for minor_version in (11, 10, 9):
-                found = shutil.which(f"python3.{minor_version}", path=python_search_path)
-                if found:
-                    python_bin = found
-                    break
-        self.configure_args.append(f"--python={python_bin}")
 
         # TODO: tests:
         # noinspection PyUnreachableCode