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

[Pádraig Brady]

Jim Meyering wrote:
> 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
> +}
> +

Looks good.
Would it be worth also warning here about components
of the path that are o+w, as that will cause test failures.
I had an untested off the cuff script for that here:

http://lists.gnu.org/archive/html/bug-coreutils/2009-11/msg00247.html

cheers,
Pádraig.