[Buildroot] [PATCH 1/2] package/gdb (7.9): fix doc build when makeinfo is missing

[Thomas Petazzoni]

Romain,

On Sat, 5 Sep 2015 23:50:33 +0200, Romain Naour wrote:

> >> + gdb/index.html: ${GDB_DOC_FILES}
> >> +-	$(MAKEHTML) $(MAKEHTMLFLAGS) $(READLINE_TEXI_INCFLAG) -I ${GDBMI_DIR} -I $(srcdir) $(srcdir)/gdb.texinfo
> >> ++	$(MAKEHTML) $(MAKEHTMLFLAGS) $(READLINE_TEXI_INCFLAG) -I ${GDBMI_DIR} -I $(srcdir) $(srcdir)/gdb.texinfo | true
> > 
> > Can you try instead to just prepend a - at the beginning of the line?
> > 
> > 	-$(MAKEHTML) ....
> > 
> 
> It doesn't work. What's the meaning of a - in this case ?

It tells make to ignore the return value of the command, and continue
executing the Makefile even if the command failed.

See https://www.gnu.org/software/make/manual/html_node/Errors.html:

"""
To ignore errors in a recipe line, write a ‘-’ at the beginning of the
line’s text (after the initial tab). The ‘-’ is discarded before the
line is passed to the shell for execution.
"""

> It's not easy to add a new options in configure.ac since a specific version of
> autoconf is needed. Also it prevent to use GDB_AUTORECONF...
> 
> configure.ac:34: error: Please use exactly Autoconf 2.64 instead of 2.69.
> 
> Another solution is to remove "doc" directory from SUBDIRS in gdb/Makefile.in:
> -SUBDIRS = doc @subdirs@ data-directory $(GNULIB_BUILDDIR)
> +SUBDIRS = @subdirs@ data-directory $(GNULIB_BUILDDIR)
> 
> Thoughts ?

Argh. So maybe, removing the "doc" directory from SUBDIRS from
Makefile.in is the easiest solution. In parallel to that, if you are
brave enough to write a patch for upstream gdb to make building the
documentation optional, and submit it, it would allow to solve the
problem for future versions of gdb. Or at least report the bug to the
gdb folks.

Thanks!

Thomas
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com