clang vs gcc for pkgsrc

[Mayuresh <mayuresh%acm.org@localhost>]

When building webkit-gtk, compiler exits with internal error - most
probably as this host has limited RAM 2GB.

On one hand I'll try building on another host with higher RAM.

On the other hand, I'd also like to try clang to see whether it works
better with limited RAM.  Would appreciate any gcc vs clang observations
in this regard (resource utilization, any issues when linking with
packages built with gcc, any noticeable differences in the quality of
optimizations performed by them etc.)

Also looked at https://wiki.netbsd.org/tutorials/pkgsrc/clang/

This line intrigues in this regard: "The caveats above about using a
consistent compiler apply."

Would appreciate more information on the caveats.

Mayuresh