Ok, thought I'd add this note here, just to make another place for someone looking for this solution... (I had to find it in multiple places...)
icu... (which I've yet to get to compile for MinGW... seems more than './configure; make' is needed, but I might try again from scratch)
If you are using Mingw/Msys/Vista, ICU may not initially build. (It will fail during 'make' with an error from '/usr/bin/install' about 'Permission denied.')
This is Vista's fault - it is requiring install to have admin privileges to run, due to its filename. You can work around this "feature" by adding "manifest" files to your Msys's bin directory, they are available here. Additionally, you may need to "touch" the executables, ie, run "touch install.exe" (Vista caches the manifests and doesn't sufficiently check if they've been changed.)
Even after all this, I'm still getting stuck. The ICU makefile enters the makefile in the data/ dir, and gets stuck. This is what seems to be hanging it up:
...but this also seems to get included in other makefiles, but the one in data locks up here. It doesn't start executing commands, running "make -nd" gives:
# The #M# is used to delete lines for icu-config
# Current full path directory.
#CURR_FULL_DIR=$(shell pwd -W)#M# for MSYS
CURR_FULL_DIR=$(subst \,/,$(shell cmd /c cd | tail --bytes=+3))#M# for Cygwin shell
# Current full path directory for use in source code in a -D compiler option.
#CURR_SRCCODE_FULL_DIR=$(subst /,\\\\,$(shell pwd -W))#M# for MSYS
CURR_SRCCODE_FULL_DIR=$(subst \,/,$(shell cmd /c cd | tail --bytes=+3))#M# for Cygwin shell
And it freezes there. I commented out the two trouble lines, replaced the one usage of them in the main ./data/Makefile with what I thought its value should be (minus shell magic) and ./data built. So, now I've just got to see if I can get the rest of this to build...
GNU Make version 3.79.1, by Richard Stallman and Roland McGrath.
Built for i686-pc-msys
Copyright (C) 1988, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 2000
Free Software Foundation, Inc.
This is free software; see the source for copying conditions.
There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A
Report bugs to <email@example.com>.
Reading makefile `Makefile'...
Reading makefile `../icudefs.mk' (search path) (no ~ expansion)...
Reading makefile `../config/mh-mingw' (search path) (no ~ expansion)...
Edit: I didn't even notice the Msys lines in there. Why are those commented... I traded the Cygwin lines for the Msys ones, and my build works. No idea why those lines are there. (There is a separate cygwin file...)
Only problem left is icu seems to compile with "-g -O2", despite being set to release and not debug.
Edit: The build also doesn't seem to produce import libraries, only dll files... >.>