warning _GL_ATTRIBUTE_SPEC_PRINTF_SYSTEM

[Mohammad Akhlaghi]

Dear Gnulib maintainers,

I just pulled the recent changes from Gnulib's 'master' branch and 
bootstrapped Gnuastro (which uses Gnulib) on my Arch GNU/Linux operating 
system.

But I got many warnings related to '_GL_ATTRIBUTE_SPEC_PRINTF_SYSTEM' in 
'error.h' and 'argp.h'. You can see some of them in the P.S, and the 
full build log (with the warnings in the middle of the build commands) 
is available in this compressed text file:

http://akhlaghi.org/gnulib-warnings.txt.gz

I will downgrade my Gnulib to the commit before the pull, and boostrap 
again for now, but it would be great if this can fixed soon (we will be 
making the next release of Gnuastro shortly).

Cheers,
Mohammad


P.S. Gnulib warnings:

/src/dir/gnuastro/bootstrapped/lib/error.h:39:6: warning: 
‘_GL_ATTRIBUTE_SPEC_PRINTF_SYSTEM’ is an unrecognized format function 
type [-Wformat=]
   39 |      ;
      |      ^
/src/dir/gnuastro/bootstrapped/lib/error.h:48:6: warning: 
‘_GL_ATTRIBUTE_SPEC_PRINTF_SYSTEM’ is an unrecognized format function 
type [-Wformat=]
   48 |      ;
      |      ^
/src/dir/gnuastro/bootstrapped/lib/argp.h:560:6: warning: 
‘_GL_ATTRIBUTE_SPEC_PRINTF_SYSTEM’ is an unrecognized format function 
type [-Wformat=]
  560 |      ;
      |      ^
/src/dir/gnuastro/bootstrapped/lib/argp.h:568:6: warning: 
‘_GL_ATTRIBUTE_SPEC_PRINTF_SYSTEM’ is an unrecognized format function 
type [-Wformat=]
  568 |      ;
      |      ^