On 10-06-2019 11:46, BoQsc wrote:

pkg-config environmental variable is empty on my system.

ldc2 `pkg-config --cflags --libs gtkd-3` hello.d

vaidas@vaidas-SATELLITE-L855:~/appd$ ldc2 `pkg-config --cflags --libs gtkd-3` hello.d
Package gtkd-3 was not found in the pkg-config search path.
Perhaps you should add the directory containing `gtkd-3.pc'
to the PKG_CONFIG_PATH environment variable
No package 'gtkd-3' found
hello.d(6): Error: module `MainWindow` is in file 'gtk/MainWindow.d' which cannot be read
import path[0] = /snap/ldc2/105/bin/../include/d/ldc
import path[1] = /snap/ldc2/105/bin/../include/d

If we are talking about Ubuntu gtkd-3.pc is installed in
/usr/lib/x86_64-linux-gnu/pkgconfig/ is that in the PKGCONFIGPATH?