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Date: Wed, 26 Aug 2015 15:49:32 -0400
From: Rich Felker <>
Subject: Re: lchmod on Linux

On Wed, Aug 26, 2015 at 09:12:30PM +0200, Tomasz Sterna wrote:
> I think there is an issue with musl providing lchmod() implementation
> on Linux.
> It simply proxies to fchmodat(), but as you cannot change mod for
> symlink on Linux it fails.
> This gives trouble to libarchive's bsdtar implementation that detects
> that platform provides lchmod, tries to use it while extracting
> archives containing symlinks and fails... ;-(
> For now I am just patching libarchive config.h to not use lchmod, but I
> would rather see musl do the right thing. :-)

This issue (the useless lchmod) was raised once before, a long time
ago. But there's not really anything that can be done about it since
there are existing binaries referencing it.

But conceptually, the same issue would exist if libarchive were using
the fchmodat function rather than lchmod. So it seems to me that the
problem is not the existence of an operation that always-fails, but
rather libarchive's misinterpretation of the result. EOPNOTSUP is a
documented result for fchmodat, and generally programs should not
treat it as an error but should just ignore it. The same should
probably be done for lchmod.


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