Re: strerror.m4 test fails incorrectly on solaris 8 and earlier [and bonus gnutls bug]

[Simon Josefsson]

Eric Blake <address@hidden> writes:

>> I found this while linking against gnutls, which uses the string
>> module, which then uses '#define strerror rpl_strerror' in its lgpl
>> library when strerror is not found.  That, in turn, leads to an
>> undefined rpl_strerror symbol in libgnutls.so.
>
> That might be a bug - if the gnulib strerror module is not in use, then
> the #define strerror rpl_strerror should not be in place.  But since it
> looks like gnutls has been subsequently fixed to avoid strerror
> altogether, I'm not sure if this still indicates any problems.

The problem is gone, but if anyone is interested, the reason the problem
occurred was that gnutls has several gnulib directories, one for LGPL
files that can be used by the library, and other gnulib directories for
GPL stuff.  The string.h module is added in the LGPL directory.  The
strerror module is added in the GPL directory.  So the strerror
re-declaration is visible even for the gnutls library that include
string.h.  For this reason, the gnutls library must be careful to avoid
ever calling strerror.  (Another reason is that strerror is
thread-unsafe so a library shouldn't use it anyway..)

/Simon