The gcc 5.5.0 compiler included with NetBSD/VAX 8.0 crashes with the default make command when invoked in the pkgsrc/shells/bash source directory, saying:
gcc -DHAVE_CONFIG_H -I. -I. -DHOST=\"vax--netbsdelf\" -DVERSION=\"20180917\" -O2 -D_FORTIFY_SOURCE=2 -c blake2b.c -o blake2b.o blake2b.c: In function 'blake2b_compress': blake2b.c:171:1: internal compiler error: in cselib_invalidate_regno, at cselib.c:2169 } ^ no stack trace because unwind library not available Please submit a full bug report, with preprocessed source if appropriate. See <http://www.NetBSD.org/support/send-pr.html> for instructions. *** Error code 1
Subsequently, "make clean" and "make install" go through fine, producing a perfectly usable bash shell.
But, "make install" does not install any useful default common bash profile in /etc/profile. A great set of bash startup files by James Robertson and modified by Dagmar d'Surreal is available at Beyond Linux From Scratch. Just their /etc/profile file by itself is sufficient for most purposes; no need to get the other bash completion, color scheme etc. related files to get by.
I was able to build and install bash successfully, and am using it as the default shell for my user-account on NetBSD/VAX.
Logging in as root produces an ignorable error from the default "sh" shell trying to process /etc/profile, not a big deal.