Add run0 as a way to raise privileges

docs/markdown/Installing.md

@@ -115,7 +115,7 @@ running `sudo meson install` will drop permissions and rebuild out of date
 targets as the original user, not as root.
 
 *(since 1.1.0)* Re-invoking as root will try to guess the user's preferred method for
-re-running commands as root. The order of precedence is: sudo, doas, pkexec
+re-running commands as root. The order of precedence is: run0, sudo, doas, pkexec
 (polkit). An elevation tool can be forced by setting `$MESON_ROOT_CMD`.
 
 ## DESTDIR support

mesonbuild/minstall.py

@@ -564,7 +564,12 @@ def do_install(self, datafilename: str) -> None:
             if is_windows() or destdir != '' or not os.isatty(sys.stdout.fileno()) or not os.isatty(sys.stderr.fileno()):
                 # can't elevate to root except in an interactive unix environment *and* when not doing a destdir install
                 raise
-            rootcmd = os.environ.get('MESON_ROOT_CMD') or shutil.which('sudo') or shutil.which('doas')
+            rootcmd = (
+                os.environ.get('MESON_ROOT_CMD')
+                or shutil.which('run0')
+                or shutil.which('sudo')
+                or shutil.which('doas')
+            )
             pkexec = shutil.which('pkexec')
             if rootcmd is None and pkexec is not None and 'PKEXEC_UID' not in os.environ:
                 rootcmd = pkexec