command not found QA: don't skip QA warnings that come from ./configure

Down through the twisting trail of history, we find a 2008 bug report
and commit 930bbbf, which disabled
detecting "command not found" in ./configure scripts with the following
rationale:

> This is actually a false positive. I'll fix it to filter out the ones that are generated by configure scripts.

As far as I can tell it wasn't a false positive though. Looking up the
source code for that old project reveals no indication that it can
misfire in "expected" ways. More generally, this obscures real issues in
configure scripts -- why should configure scripts be special here? --
which have *zero* guarantee of resulting in failure. Anecdotally, they
usually do not.

Whatever the underlying issue is, it's *definitely* an upstream bug and
*almost certainly* indicates that there may be situations where the
project miscompiles against expectations.

Bug: https://bugs.gentoo.org/245716
Signed-off-by: Eli Schwartz <[email protected]>

lib/portage/package/ebuild/doebuild.py

@@ -2275,7 +2275,6 @@ def _check_build_log(mysettings, out=None):
         r"(.*): line (\d*): (.*): command not found$"
     )
     dash_command_not_found_re = re.compile(r"(.*): (\d+): (.*): not found$")
-    command_not_found_exclude_re = re.compile(r"/configure: line ")
     helper_missing_file = []
     helper_missing_file_re = re.compile(r"^!!! (do|new).*: .* does not exist$")
 
@@ -2379,16 +2378,10 @@ def _eerror(lines):
             ):
                 am_maintainer_mode.append(line.rstrip("\n"))
 
-            if (
-                bash_command_not_found_re.match(line) is not None
-                and command_not_found_exclude_re.search(line) is None
-            ):
+            if bash_command_not_found_re.match(line) is not None:
                 command_not_found.append(line.rstrip("\n"))
 
-            if (
-                dash_command_not_found_re.match(line) is not None
-                and command_not_found_exclude_re.search(line) is None
-            ):
+            if dash_command_not_found_re.match(line) is not None:
                 command_not_found.append(line.rstrip("\n"))
 
             if helper_missing_file_re.match(line) is not None: