autoconf macros not working as expected

[Josh Datko]

I have a C autotools project with guile extensions that I'm trying to
cross-compile, however even when I think I'm disabling building the
extensions (--without-guile), it appears that configure is trying to
check for guile. Then configure fails, because, well there's no guile
for my cross compile target.

In my configure.ac I have the following snippets:

AC_ARG_WITH([guile],
        AS_HELP_STRING([--with-guile], [Build the guile extensions]))
AM_CONDITIONAL([HAVE_GUILE], [test "x$with_guile" = "xyes"])

<<snip>>


AS_IF([test "x$with_guile" = "xyes"], [
# Guile Extensions
echo "Checking for guile extensions"
PKG_CHECK_MODULES([GUILE], [guile-2.0])
GUILE_PROGS
GUILE_FLAGS
GUILE_SITE_DIR
])

I'm configuring like this:

$ PKG_CONFIG_LIBDIR=../pkg-config ./configure --host=arm-linux-musleabi 
--without-guile
checking for arm-linux-musleabi-gcc... arm-linux-musleabi-gcc
checking whether the C compiler works... yes
<<snip>>
checking pkg-config is at least version 0.9.0... yes
configure: checking for guile 2.0
configure: checking for guile 1.8
configure: error: 
No Guile development packages were found.

Please verify that you have Guile installed.  If you installed Guile
from a binary distribution, please verify that you have also installed
the development packages.  If you installed it yourself, you might need
to adjust your PKG_CONFIG_PATH; see the pkg-config man page for more.

I'm on Ubuntu 16.04 with the following versions of things:

autoconf: 2.69
Guile: guile (GNU Guile) 2.0.11
Packaged by Debian (2.0.11-deb+1-10)


I would have expected that the guile macros only check for guile if --
with-guile was passed.

Thanks,

Josh