Missing transitive cflags (Regression) #385
Description
pkgconf 2.4.0/2.4.1 doesn't output all cflags from transitive dependencies (Requires).
$ PKG_CONFIG_PATH=$PWD/installed/x64-linux/debug/lib/pkgconfig ./installed/x64-linux/tools/pkgconf/pkgconf glib-2.0 --cflags
-I/home/vcpkg/vcpkg/installed/x64-linux/debug/lib/pkgconfig/../../../include/glib-2.0 -pthread -I/home/vcpkg/vcpkg/installed/x64-linux/debug/lib/pkgconfig/../../lib/glib-2.0/include -I/home/vcpkg/vcpkg/installed/x64-linux/debug/lib/pkgconfig/../../../include
$ grep Requires $PWD/installed/x64-linux/debug/lib/pkgconfig/pango.pc
Requires: glib-2.0 >= 2.80, gobject-2.0 >= 2.80, gio-2.0 >= 2.80, fribidi >= 1.0.6, harfbuzz >= 8.4.0, fontconfig >= 2.15.0, freetype2, cairo >= 1.18.0
$ PKG_CONFIG_PATH=$PWD/installed/x64-linux/debug/lib/pkgconfig ./installed/x64-linux/tools/pkgconf/pkgconf $PWD/installed/x64-linux/debug/lib/pkgconfig/pango.pc --cflags
-I/home/vcpkg/vcpkg/installed/x64-linux/debug/lib/pkgconfig/../../../include/pango-1.0 -I/home/vcpkg/vcpkg/installed/x64-linux/debug/lib/pkgconfig/../../../include -pthread -I/home/vcpkg/vcpkg/installed/x64-linux/debug/lib/pkgconfig/../../../include/glib-2.0 -I/home/vcpkg/vcpkg/installed/x64-linux/debug/lib/pkgconfig/../../../include/fribidi -I/home/vcpkg/vcpkg/installed/x64-linux/debug/lib/pkgconfig/../../../include/harfbuzz -I/home/vcpkg/vcpkg/installed/x64-linux/debug/lib/pkgconfig/../../../include/cairo -DXML_STATIC -I/home/vcpkg/vcpkg/installed/x64-linux/debug/lib/pkgconfig/../../../include/libpng16 -I/home/vcpkg/vcpkg/installed/x64-linux/debug/lib/pkgconfig/../../../include/pixman-1 -pthread
So pango.pc requires glib-2.0, but -I/home/vcpkg/vcpkg/installed/x64-linux/debug/lib/pkgconfig/../../lib/glib-2.0/include doesn't show with --cflags for pango.pc. (And this is the dir having glib config.h.)
The problem doesn't occur with 2.3.0.