[tlbuild] MinGW cross-compiling, settings CFLAGS/LDFLAGS etc.

[Mojca Miklavec]

Hi,

Luigi has spent quite some time testing the cross-compiler, but I'm
still struggling to make it work correctly (ideally on my Mac, so that
I can test more easily; Luigi tested on Linux).

(1)
The biggest issue has always been ICU, in one way or another. For
example, at the moment it fails for me with

make[5]: Making `all' in `stubdata'
generating dependency information for
/path/to/source/Work/libs/icu/../../../libs/icu/icu-src/source/stubdata/stubdata.cpp
stubdata.d:1: *** missing separator.  Stop.
make[5]: *** [all-recursive] Error 2
make[4]: *** [icubuild] Error 2

The file ./Work/libs/icu/icu-build/stubdata/stubdata.d starts with the
following two lines

    -n stubdata.d
    stubdata.o: \

while the icu-native starts with the following line

    stubdata.d stubdata.o stubdata.ao: \

and then both followed by a list of files.

(2)
if I don't provide any special flags, while using the flags suggested
by Luigi (-fno-lto -fno-use-linker-plugin -static-libgcc
-static-libstdc++) leads to a mixup: I don't know how to only apply
those flags to the cross-compiler, while leaving the native compiler
(used for icu-native) alone. On mac the clang compiler doesn't support
most of those flags and the build is simply broken.

(3)
Random reported errors which don't seem to be fatal:

libtool:   error: Could not determine the host path corresponding to
libtool:   error:   '/path/to/source/Work/texk/kpathsea/.libs'
libtool:   error: Continuing, but uninstalled executables may not work.
libtool:   error: Could not determine the host path corresponding to
libtool:   error:
'/path/to/source/Work/texk/kpathsea/.libs:/path/to/source/inst/lib:/path/to/source/inst/bin'
libtool:   error: Continuing, but uninstalled executables may not work.

(4)
While building subcomponents, I often get another non-fatal warning about:
    configure: WARNING: using cross tools not prefixed with host triplet
as if that setting is somehow lost / not passed to other configure scripts.

(5)
Somewhat unrelated, but since I'm in the middle of the email anyway,
these flags from ./Build --help seem like a leftover from the last
year when one would build luatex and luatex53 as separate binaries:

  --disable-luatex          do not compile and install LuaTeX
  --disable-luatex53        do not compile and install LuaTeX53
  --disable-luajittex       do not compile and install LuaJITTeX

I believe this is no longer the case, so I assume the luatex53 flag
could go for good?

(6)
Running ./Build --help leads to errors and breaks the build if another
build in the same directory is already running. Is there any way to
avoid this?

Mojca