[Gm2] Building gm2-9.1.0 under Arch Linux

[Geert Theloosen]

Hi,

In the recent past I succeeded in building gm2 (8.2.0) under Arch Linux, 
but for me this building was always on a somewhat mysterious way. So I 
tried building a new gm2-9.1.0-branch, and at the end I succeeded, but 
on the same somewhat inexplicable way.
Maybe some Arch Linux users can take advantage of the at the end 
successful build, but for me it's about the hurdles.
After downloading gcc-9.1.0+gm2-git-latest.tar.gz and unpacking it,
I changed the shebang of

../gcc-9.1.0+gm2-git-latest/gm2/gcc-versionno/gcc/gm2/tools-src/def2texi.py

because Arch Linux uses Python-3 as the default and the script assumes 
Python-2, to:
#!/usr/bin/python2.

Then I used the Debian gcc-8.2.0 build script and changed the version 
numbering and changed [--enable-languages=c,c++,m2] to [...=c,c++,gm2].
So these are my used commands:

$ mkdir build-9.1.0
$ cd build-9.1.0
$ CXXFLAGS=-g BOOT_CFLAGS=-g CFLAGS=-g \
  ../gcc-9.1.0+gm2-git-latest/gm2/gcc-versionno/configure \
  --prefix=$HOME/opt \
  --libexecdir=$HOME/opt/lib \
  --enable-threads=posix \
  --enable-clocale=gnu --enable-languages=c,c++,gm2 \
  --disable-multilib --disable-bootstrap --enable-checking

After doing

$ make

I got the following error message:
...

python 
../../gcc-9.1.0+gm2-git-latest/gm2/gcc-versionno/gcc/gm2/tools-src/def2texi.py 
-uLibraries -s../../gcc-9.1.0+gm2-git-latest/gm2/gcc-versionno/gcc/gm2 
-b/home/geert/Downloads/modula-2/build-9.1.0/gcc/gm2 > 
/home/geert/Downloads/modula-2/build-9.1.0/gcc/gm2/gm2-libs.texi
  File 
"../../gcc-9.1.0+gm2-git-latest/gm2/gcc-versionno/gcc/gm2/tools-src/def2texi.py", 
line 62
    print "@node " + l[1] + ", " + next + ", " + previous+ ", " + up
                 ^
SyntaxError: Missing parentheses in call to 'print'. Did you mean 
print("@node " + l[1] + ", " + next + ", " + previous + ", " + up)?
make[2]: *** 
[../../gcc-9.1.0+gm2-git-latest/gm2/gcc-versionno/gcc/gm2/Make-lang.in:237: 
gm2/gm2-libs.texi] Fout 1
make[2]: Map '/home/geert/Downloads/modula-2/build-9.1.0/gcc' wordt verlaten
make[1]: *** [Makefile:4354: all-gcc] Fout 2
make[1]: Map '/home/geert/Downloads/modula-2/build-9.1.0' wordt verlaten
make: *** [Makefile:970: all] Fout 2

('Fout' (Dutch) means 'error')

But in a previous step I changed the shebang of def2texi.py. So I can't 
explain the error message. Or, perhaps because python (under Arch Linux 
this is python3) is calling python2?
However, just doing a [make] again without changing anything builds 
everything correctly. How is that possible?
Then, doing a [make install] gives a $HOME/opt directory with the 
binaries, libraries, etc.
Incidentally, I have once before added to my .bashrc: export 
GM2_ROOT=/home/geert/opt
Compiling a simple helloworld.mod with a not recognised Modula command 
('WritString') with [gm2 -Wall -fmakeall] gives colourized error 
messages, Correcting the error and again compiling the file gives the 
expected a.out.
My question: why does the building succeeds after doing [make] twice 
without correcting anything between the two calls?
Sincerely,
Geert Theloosen