bug#45545: gsasl fails to build on aarch64

[Caliph Nomble]

Hi,

The package gsasl fails to cross-compile to aarch64 on an x86_64 machine
(tested most recently on commit 8e128df5bf), at least, on mine. It seems to not
recognize libgcrypt during configure, even though it's listed in the package's
inputs. The build log is long, so I'll just list the important parts:

> ...
> phase `patch-source-shebangs' succeeded after 0.2 seconds
> starting phase `configure'
> configure flags: ("CC_FOR_BUILD=gcc" 
> "CONFIG_SHELL=/gnu/store/pwcp239kjf7lnj5i4lkdzcfcxwcfyk72-bash-minimal-5.0.16/bin/bash"
>  
> "SHELL=/gnu/store/pwcp239kjf7lnj5i4lkdzcfcxwcfyk72-bash-minimal-5.0.16/bin/bash"
>  "--prefix=/gnu/store/5isgg257zhlfczz20nf2rza2fibfaw7q-gsasl-1.8.1" 
> "--enable-fast-install" "--build=x86_64-unknown-linux-gnu" 
> "--host=aarch64-linux-gnu" "--with-gssapi-impl=mit" "--disable-static")
> ...
> checking for __builtin_expect... yes
> checking byteswap.h usability... yes
> checking byteswap.h presence... yes
> checking for byteswap.h... yes
> checking for libgcrypt-config... no
> checking for LIBGCRYPT - version >= 1.4.4... no
> configure: error: libgcrypt is too old
> configure: error: ./configure failed for lib
> command 
> "/gnu/store/pwcp239kjf7lnj5i4lkdzcfcxwcfyk72-bash-minimal-5.0.16/bin/bash" 
> "./configure" "CC_FOR_BUILD=gcc" 
> "CONFIG_SHELL=/gnu/store/pwcp239kjf7lnj5i4lkdzcfcxwcfyk72-bash-minimal-5.0.16/bin/bash"
>  
> "SHELL=/gnu/store/pwcp239kjf7lnj5i4lkdzcfcxwcfyk72-bash-minimal-5.0.16/bin/bash"
>  "--prefix=/gnu/store/5isgg257zhlfczz20nf2rza2fibfaw7q-gsasl-1.8.1" 
> "--enable-fast-install" "--build=x86_64-unknown-linux-gnu" 
> "--host=aarch64-linux-gnu" "--with-gssapi-impl=mit" "--disable-static" failed 
> with status 1

The specific configure script failing seems to be lib/configure. Tell me if,
and how, I should include any more of the log.

This seems to be more of a problem since commit 72861d8ed4, since rottlog now
indirectly depends on gsasl, and rottlog is one of the base services. The
following command, thus, replicates the issue:

> guix system disk-image --image-type=pine64-raw -e '(@ (gnu system images 
> pine64) pine64-barebones-os)'

Thanks!