Re: [mosquitto-dev] patches from pkgsrc for discussion, based on 1.6.1

[Christoph Willing <chris.willing@xxxxxxxxx>]

On 29/4/19 8:43 am, Greg Troxel wrote:
> Christoph Willing <chris.willing@xxxxxxxxx> writes:
> 
>> From the pkg-config manpage (about PKG_CONFIG_PATH):
>>
>> "the default is libdir/pkgconfig:datadir/pkgconfig where libdir is the
>> libdir for pkg-config and datadir is the datadir for pkg-config when it
>> was installed."
>>
>> On Slackware64, libdir is lib64 so that's where pkgconfig has
>> traditionally been located (/usr/lib64/pkgconfig). However I notice that
>> some packages are installing pkgconfig into datadir (which becomes
>> /usr/share/pkgconfig here).
>>
>> Clearly, according to the manpage, both locations will work although I'm
>> unsure as to what the difference actually means and why would one be
>> chosen in preference to the other. Given that both locations are
>> acceptable, the patch to revert back to libdir/pkgconfig may not be
>> necessary.
> 
> Thanks.  Another question is if it can be proven that the pkgconfig file
> for a given package will be the same on all architectures.  This is also
> necessary for a .pc file to be safely installed in
> ${PREFIX}/share/pkgconfig, even if it's true that this location will be
> searched.
> 

Well I think it's contents should differ according to the architecture.
That's partly what it exists for, to point to correct library locations
(which may be architecture dependent).

Speaking of which, due to this discussion I was checking the contents of
the installed libmosquitto.pc and libmosquittopp.pc here and found both
to be wrong. They both say:
    libdir=${exec_prefix}/lib

which is OK for many systems but not all, in particular those with lib
or lib64 directories depending on architecture.


Roger,
   Would you consider including the following change please? It will
change libmosquitto.pc and libmosquittopp.pc only if LIB_SUFFIX is
specified during configuration e.g. -DLIB_SUFFIX=64 (as we commonly do
on Slackware 64bit). If LIB_SUFFIX is not configured, nothing changes.

Thanks,
chris

--- libmosquitto.pc.in.orig     2019-04-27 02:07:59.000000000 +1000
+++ libmosquitto.pc.in  2019-04-29 17:33:00.802053837 +1000
@@ -1,7 +1,7 @@
 prefix=@CMAKE_INSTALL_PREFIX@
 exec_prefix=${prefix}
 includedir=${prefix}/include
-libdir=${exec_prefix}/lib
+libdir=${exec_prefix}/lib@LIB_SUFFIX@

 Name: mosquitto
 Description: mosquitto MQTT library (C bindings)
--- libmosquittopp.pc.in.orig   2019-04-27 02:07:59.000000000 +1000
+++ libmosquittopp.pc.in        2019-04-29 17:33:23.034679206 +1000
@@ -1,7 +1,7 @@
 prefix=@CMAKE_INSTALL_PREFIX@
 exec_prefix=${prefix}
 includedir=${prefix}/include
-libdir=${exec_prefix}/lib
+libdir=${exec_prefix}/lib@LIB_SUFFIX@

 Name: mosquittopp
 Description: mosquitto MQTT library (C++ bindings)