Re: Build failures of coreutils-8.1 in Fedora build system "koji"

[Jim Meyering]

Jim Meyering wrote:
...
>> execve("/root/bin/no_such", ["no_such"], [/* 57 vars */]) = -1 EACCES 
>> (Permission denied)
> ...
>> /root/bin/ directory is not created in koji buildroot (it is not created by 
>> default at all) - so that might be the difference.
>
> Thanks!  The problem is that your PATH contains a
> directory that disallows search access:
>
>     $ (mkdir d && chmod u-x d && export PATH=d:$PATH; env no-such )
>     env: no-such: Permission denied
>     [Exit 126]
>
> in that case, execve fails with permission denied.
>
> I've just confirmed that Solaris 10's env command also
> exits with status 126 in this case.
>
> I think the best way to fix this problem is to add a new predicate
> that skips the test when PATH contains an unsearchable directory.
>
> Or better still: just rewrite PATH to exclude any such directory.

Here's a patch to do just that:

Note that while I'm using "local" here, it's not the first use.
There's at least one existing use in require_proc_pid_status_.

Technically using "local" is not good from a portability standpoint, but it
seems better in the long run than continually obfuscating local variable
names with trailing underscores.  People with a losing shell can simply
skip the tests or first install a modern shell.

>From ab6b27eba720c04da91f5300121a6fe06d1fa9b4 Mon Sep 17 00:00:00 2001
From: Jim Meyering <address@hidden>
Date: Mon, 23 Nov 2009 17:35:20 +0100
Subject: [PATCH] tests: avoid test failures when PATH contains an unsearchable 
directory

* tests/test-lib.sh (sanitize_path_): New function.
Always call it.
---
 tests/test-lib.sh |   28 +++++++++++++++++++++++++++-
 1 files changed, 27 insertions(+), 1 deletions(-)

diff --git a/tests/test-lib.sh b/tests/test-lib.sh
index 456a30a..06087ea 100644
--- a/tests/test-lib.sh
+++ b/tests/test-lib.sh
@@ -23,6 +23,31 @@ if test $? != 11; then
   Exit 77
 fi

+# Having an unsearchable directory in PATH causes execve to fail with EACCES
+# when applied to an unresolvable program name, contrary to the desired ENOENT.
+# Avoid the problem by rewriting PATH to exclude unsearchable directories.
+sanitize_path_()
+{
+  local saved_IFS=$IFS
+    IFS=:
+    set - $PATH
+  IFS=$saved_IFS
+
+  local d d1
+  local colon=
+  local new_path=
+  for d in "$@"; do
+    test -z "$d" && d1=. || d1=$d
+    if ls -d "$d1/." > /dev/null 2>&1; then
+      new_path="$new_path$colon$d"
+      colon=':'
+    fi
+  done
+
+  PATH=$new_path
+  export PATH
+}
+
 skip_test_()
 {
   echo "$0: skipping test: $@" | head -1 1>&9
@@ -54,7 +79,6 @@ require_selinux_enforcing_()
     || skip_test_ "This test is useful only with SELinux in Enforcing mode."
 }

-
 require_openat_support_()
 {
   # Skip this test if your system has neither the openat-style functions
@@ -396,5 +420,7 @@ else
   compare() { cmp "$@"; }
 fi

+sanitize_path_
+
 # Initialize; all bourne shell scripts end with "Exit $fail".
 fail=0
--
1.6.6.rc0.203.g7074f