Hello,
I've been trying to get WebkitFLTK[1] working on Alpine, and I have it
building.
But as usual, that's the easy part. The test program, 
Source/WebKit/fltk/testapp/testapp, segfaults in do_relocs.
I'm attaching the output of bt full.

Build dependencies include:
g++ >= 4.7.3
python2 perl ruby 
icu-dev cairo-dev harfbuzz-dev libxslt-dev sqlite-dev fltk-dev

harfbuzz must be built with ICU, as alpine does; fltk must be 1.3.3
or later; Alpine provides python2 as python.

Build directions are in README.asciidoc, and amount to:
make -C Source/WTF/wtf && \
make -C Source/JavaScriptCore gen && \
make -C Source/JavaScriptCore && \
make -C Source/WebCore && \
make -C Source/WebKit/fltk


Additionally, at least a gig of RAM per thread will be needed,
and a very fast processor or lots of time.
On my laptop with an Atom N270 and a gigabyte of ram, I get 
occasional swap thrashing, and the compilation takes a little over
11 hours.

So if someone who has a faster system can look at this, I'd be
grateful.

Thank you,
Isaac Dunham

[1] https://github.com/clbr/webkitfltk