[Buildroot] [PATCH] support/dependencies: ensure we have 'file' on the host

[Arnout Vandecappelle <arnout@mind.be>]

On 27-11-15 21:02, Yann E. MORIN wrote:
> When 'file' is missing on the host, libtool fails miserably. Packages
> that use libtool will suddenly FTBFS, with cryptic error messages, like
> missing libraries on the linker invocation.
> 
> We could ensure that autotools based packages now all depend on
> host-file. But It itself is an autotools package, so it's again a
> chicken-n-egg issue. And even non-autotools package may use libtool.
> 
> So, just require that 'file' is present on the host.

 Improved commit message:

support/dependencies: ensure we have 'file' on the host

Recently, the libtool.m4 autoconf macros that are bundled with the libtool
package started using '/usr/bin/file' to determine the type of library that
is generated by the toolchain. Packages that use this macro will fail in a
rather dramatic way when /usr/bin/file is not present on the host: the
package will still build but no shared library is generated, which in turn
may cause build failures in other packages that link with it.

For example, libpng's configure determines that it is not possible to build
a shared library on MIPS64 because the expected output from 'file' is not
present. Therefore, only a static libpng.a is built. Later, bandwithd links
with -lpng but it doesn't use the pkg-config's Private-Libs (because it's
not linking statically) and it doesn't have access to the NEEDED reference
from the shared library. Therefore, it doesn't link with zlib and fails with

pngrutil.c:(.text+0x55c): undefined reference to `inflate'

Since we can expect more packages to behave like this in the future, just
require that '/usr/bin/file' is present on the host unconditionally.



> 
> Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
> ---
>  support/dependencies/dependencies.sh | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/support/dependencies/dependencies.sh b/support/dependencies/dependencies.sh
> index 3146401..f14fb79 100755
> --- a/support/dependencies/dependencies.sh
> +++ b/support/dependencies/dependencies.sh
> @@ -69,6 +69,12 @@ check_prog_host "which"
>  # Verify that sed is installed
>  check_prog_host "sed"
>  
> +# 'file' must be present, otherwise libtool fails in incomprehensible
> +# ways. For example, bandwidthd would fail to link with -lz, even
> +# though the library is there (and it's not a static/shared issue).
> +# Adding the 'file' program on the system miraculously fixes the issue.
> +check_prog_host "file"

 This is actually not good enough: it really has to be /usr/bin/file (so adding
host-file would in fact not help at all).


> +
>  # Check make
>  MAKE=$(which make 2> /dev/null)
>  if [ -z "$MAKE" ] ; then
> 


-- 
Arnout Vandecappelle                          arnout at mind be
Senior Embedded Software Architect            +32-16-286500
Essensium/Mind                                http://www.mind.be
G.Geenslaan 9, 3001 Leuven, Belgium           BE 872 984 063 RPR Leuven
LinkedIn profile: http://www.linkedin.com/in/arnoutvandecappelle
GPG fingerprint:  7493 020B C7E3 8618 8DEC 222C 82EB F404 F9AC 0DDF