[tlbuild] m-tx test fails on powerpc-linux

[Karl Berry]

Hi Johannes,

    The output comes from the fprintf call ending on "%d\n" at line 1131

I see that line ending with %s\n, not %d:
  fprintf(outfile, " %s %8.5f %d %d %d %d %s\n",
  
I suspect that the fracindent variable corresponding to the %s is NULL
at the point of the fprintf, and Thomas (Schmitz)'s libc (Debian 6)
printed that as 0, and yours prints it as garbage. I.e., the bug was
present before but hidden. 

1) Try compiling without optimization.

2) If you have valgrind or similar available, couldn't hurt to try
running that.

3) Failing that, I can only suggest running under the debugger and
try to discern where the bad value comes from.

I can ask Thomas if he happens to have binaries from last year with
symbols included. (Or maybe you can get a debuggable 2017 binary from a
Debian or other archive?) Then you could run the two side by side and
see where they diverge. Or maybe try doing that with a supposedly-good
binarch (e.g., your aarch64) and the failing powerpc.

    prepmx emits some more warnings during processing:

Sounds like something went wrong earlier :(. -k