Re-merging umix fails for me:
x86_64-pc-linux-gnu-gcc -march=amdfam10 -O2 -ggdb -pipe -Wall -Wl,--as-needed -o
umix umix_common.o umix.o mixer.o error.o ui.o ui_ncurses.o -lncurses
i_ncurses.o: undefined reference to symbol 'cbreak'
/lib64/libtinfo.so.6: error adding symbols: DSO missing from command line
collect2: error: ld returned 1 exit status
Makefile:200: recipe for target 'umix' failed
make: *** [umix] Error 1
Previous version has been around since 2009 on my system, and I guess I enabled the tinfo USE flag for ncurses after that.
Got bitten by this again during the world rebuild for the 17.0 profile migration. Guess I'll unmerge umix for now.
This issue has been fixed by the following commit:
Author: Jeroen Roovers <email@example.com>
Date: Fri Mar 2 09:49:10 2018
media-sound/umix: Fix building against sys-libs/ncurses[tinfo] (bug #647164).
Package-Manager: Portage-2.3.24, Repoman-2.3.6