radare2 comes with capstone and few other deps by default. There is a configure script to system library: $(use_with capstone syscapstone) Please unbind that library
we have a working ebuild which uses system capstone, radare2-bindings. Have a look here: https://github.com/pentoo/pentoo-overlay/tree/master/dev-util/radare2 https://github.com/pentoo/pentoo-overlay/tree/master/dev-libs/radare2-bindings
While I agree the knob needs to be exposed i'm not sure it's safe to use current 3.0.4 gentoo's capstone as is. radare2 applies 3 (small) patches on capstone: https://github.com/radare/radare2/tree/master/shlr/capstone-patches and usually pin to relatively recent git capstone release: https://github.com/radare/radare2/blob/master/shlr/Makefile#L22 AFAIU those commits are not capstone releases.
I'll try to add Quynh to comment. He is very responsive and willing to fix such bugs usually. The main reason why you added capstone under "dev-libs" so that it could be shared. I'm working on adding at least one more tool called "frida" (https://github.com/aquynh/capstone/issues/757) with similar problem. It would be good to have one library installed at the end.
Took me too long. My apologies. Pushed as: https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=8b23a01ee9c711bd6faec409c95c0b46f76abef2 Thanks for the report!
