I searched through the forum and did not find something similar.
I am using Gentoo and I tried to figure out how does “Browse Packages…” button work, cause I have Midnight Commander as file manager and do not want to install Thunar/Nautilus/whatever-you-use. When I straced ST3, I noticed that it tries to open /usr/lib64/libappmenu.so and /lib64/libappmenu.so. Google said me that is an OS X-like menu that exists only in Ubuntu (or rather Unity). Ubuntu is not the only distro that exists in world, please, fix this.