Introduction

This is a shorter post, following up on the Loose Ends section of the cross-the-gir.

After dealing with the fallout from merging gir support, there wasn't much to do, glibc-2.29 is still waiting. I decided to take some time to find out why libgusb is failing.

Diagnostics

#error

First thing we need to do is to look at the error, we can re-use the error message from the last article. Let's take a look at where it actually errors out

In file included from /builddir/libgusb-0.3.0/build/g-ir-cpp-se2xrgqu.c:4:
/builddir/libgusb-0.3.0/build/gusb/gusb-version.h:31:2: error: #error "Only <gusb.h> can be included directly."
 #error "Only <gusb.h> can be included directly."
  ^~~~~

OK, we are hitting a #error directive in build/gusb/gusb-version.h, on line 31, let's take a peek at it and a few lines around.

#if !defined (__GUSB_INSIDE__) && !defined (GUSB_COMPILATION)
#error "Only <gusb.h> can be included directly."
#endif

Interesting, we need either __GUSB_INSIDE__ or GUSB_COMPILATION defined. But where is it defined ?

meson.build

add_project_arguments('-DGUSB_COMPILATION', language: 'c')

So it is added to the project CFLAGS, isn't it present in the args passed to it ? Let's check the build.ninja for it.

build/build.ninja

build
gusb/GUsb-1.0.gir:
CUSTOM_COMMAND

|
/usr/aarch64-linux-gnu/usr/bin/g-ir-scanner
gusb/libgusb.so.2.0.10

COMMAND
=
/usr/aarch64-linux-gnu/usr/bin/g-ir-scanner
-pthread
-I/usr/aarch64-linux-gnu/usr/include/gobject-introspection-1.0
-I/usr/aarch64-linux-gnu/usr/include/glib-2.0
-I/usr/aarch64-linux-gnu/usr/lib/glib-2.0/include
--no-libtool
--namespace=GUsb
--nsversion=1.0
--warn-all
--output
gusb/GUsb-1.0.gir
--c-include=gusb.h
-I/builddir/libgusb-0.3.0/gusb
-I/builddir/libgusb-0.3.0/build/gusb
-I./.
-I../.
-I./gusb/.
-I../gusb/.
--filelist=/builddir/libgusb-0.3.0/build/gusb/bf6bc9e@@gusb@sha/GUsb_1.0_gir_filelist
-L/builddir/libgusb-0.3.0/build/gusb
--extra-library=gusb
--include=Gio-2.0
--include=GObject-2.0
--symbol-prefix=g_usb
--identifier-prefix=GUsb
--pkg-export=gusb
--cflags-begin
-I./.
-I../.
-I./gusb/.
-I../gusb/.
-I/usr/aarch64-linux-gnu/usr/include/libmount
-I/usr/aarch64-linux-gnu/usr/include/blkid
-I/usr/aarch64-linux-gnu/usr/include/uuid
-I/usr/aarch64-linux-gnu/usr/include/glib-2.0
-I/usr/aarch64-linux-gnu/usr/lib/glib-2.0/include
-I/usr/aarch64-linux-gnu/usr/include/libusb-1.0
-D_FORTIFY_SOURCE=2
-I/usr/aarch64-linux-gnu/usr/include
--cflags-end
--library
gusb
-L/builddir/libgusb-0.3.0/build/gusb
-L/usr/aarch64-linux-gnu/usr/lib
--extra-library=gio-2.0
--extra-library=gobject-2.0
--extra-library=glib-2.0
--extra-library=usb-1.0

Looking at ATK

Taking a look at another package that uses both meson and generates gir, Atk.

Let's check if they also have an equivalent to GUSB_COMPILATION, maybe ATK_COMPILATION ?

atk/meson.build

atk_cflags = [
  '-DG_LOG_DOMAIN="Atk"',
  '-DG_LOG_USE_STRUCTURED=1',
  '-DGLIB_DISABLE_DEPRECATION_WARNINGS',
  '-DATK_DISABLE_DEPRECATION_WARNINGS',
  '-DATK_COMPILATION',
  '-DATK_LOCALEDIR="@0@"'.format(join_paths(atk_datadir, 'locale')),
]
if get_option('introspection')
  gnome.generate_gir(libatk,
                     sources: atk_sources + atk_headers + [ atk_enum_h ] + [ atk_version_h ],
                     namespace: 'Atk',
                     nsversion: atk_api_version,
                     identifier_prefix: 'Atk',
                     symbol_prefix: 'atk',
                     export_packages: 'atk',
                     includes: [ 'GObject-2.0' ],
                     install: true,
                     extra_args: [
                       '--quiet',
                       '--c-include=atk/atk.h',
                       '-DATK_COMPILATION',
                     ])
endif

They do, and they pass it via extra_args, not add_project_arguments. Well then, let's modify libgusb to also do it.

Fixing

patching

Let's patch the package.

diff --git a/gusb/meson.build b/gusb/meson.build
index 5276259..b6a04d5 100644
--- gusb/meson.build
+++ gusb/meson.build
@@ -113,6 +113,7 @@ libgusb_girtarget = gnome.generate_gir(gusb,
   export_packages : 'gusb',
   extra_args : [
     '--c-include=gusb.h',
+    '-DGUSB_COMPILATION',
     ],
   link_with : gusb,
   dependencies : [

building

Looks good enough, let's try building it.

$ xbps-src -f -a aarch64 pkg libgusb
=> Registering new packages to /host/binpkgs/libgusb
index: added `libgusb-0.3.0_4' (aarch64).
index: added `libgusb-devel-0.3.0_4' (aarch64).
index: 2 packages registered.
$ env XBPS_TARGET_ARCH=aarch64 xls libgusb{,-devel} | grep -E ',(gir|typelib)
/usr/lib/girepository-1.0/GUsb-1.0.typelib
/usr/share/gir-1.0/GUsb-1.0.gir

Upstreaming

A problem is rarely fixed unless it is upstream, so lets make a pull request.

Closing out

This has been a very annoying bug, that is now fixed.