[tlbuild] Compiling asy with recent gcc

[Nelson H. F. Beebe]

Ken Brown <kbrow1i at gmail.com> reports a failure in building Asymptote
on Cygwin with gcc-9.2.0 (newly upgraded from gcc-7.4.x):

>> When I build asy with this compiler it crashes in the sort2 test.
>> Running the test under gdb shows that there's a null pointer
>> dereference in GC_free (hhdr is null). If I build without
>> optimization, the problem doesn't occur.

I just scanned all of the asy executables available at

    http://www.math.utah.edu/pub/texlive-utah/bin

and found that TeX Live 2020 for these files were built with a gcc-9.x
>> compiler:

    amd64-clonos19/asy              GCC: (FreeBSD Ports Collection) 9.2.0
    amd64-freebsd130/asy            GCC: (FreeBSD Ports Collection) 9.2.0
    amd64-hardenedbsd13/asy         GCC: (FreeBSD Ports Collection) 9.1.0
    x86_64-arco19/asy               GCC: (GNU) 9.2.0
    x86_64-blackarch/asy            GCC: (GNU) 9.2.0
    x86_64-budgie1910/asy           GCC: (Ubuntu 9.2.1-9ubuntu2) 9.2.1 20191008
    x86_64-centos8/asy              GCC: (GNU) 9.1.1 20190605 (Red Hat 9.1.1-2)
    x86_64-fedora30/asy             GCC: (GNU) 9.2.1 20190827 (Red Hat 9.2.1-1)
    x86_64-fedora31/asy             GCC: (GNU) 9.2.1 20190827 (Red Hat 9.2.1-1)
    x86_64-kali-2/asy               GCC: (Debian 9.2.1-25) 9.2.1 20200123
    x86_64-kaos2020/asy             GCC: (GNU) 9.2.0
    x86_64-manjaro19/asy            GCC: (GNU) 9.2.1 20200130 GCC: (Arch Linux 9.2.1+20200130-2) 9.2.1 20200130
    x86_64-openmandriva41-clang/asy GCC: (GNU) 9.2.1 20191109 (OpenMandriva) GCC: (GNU) 9.2.1 20191207 (OpenMandriva)
    x86_64-openmandriva41/asy       GCC: (GNU) 9.2.1 20191109 (OpenMandriva) GCC: (GNU) 9.2.1 20191207 (OpenMandriva)
    x86_64-opensusetw2/asy          GCC: (SUSE Linux) 9.2.1 20190903 [gcc-9-branch revision 275330]
    x86_64-oracle8/asy              GCC: (GNU) 9.1.1 20190605 (Red Hat 9.1.1-2)
    x86_64-slackware15/asy          GCC: (GNU) 9.2.0
    x86_64-trident-void-linux/asy   GCC: (GNU) 9.1.0 GCC: (GNU) 9.2.0
    x86_64-ubuntu1910/asy           GCC: (Ubuntu 9.2.1-9ubuntu2) 9.2.1 20191008
    x86_64-ubuntu2004/asy           GCC: (Ubuntu 9.2.1-21ubuntu1) 9.2.1 20191130

With rare exceptions, I do not supply optimization levels when I build
TeX Live snapshots, and I don't install a build at the above URL if
there are segmentation faults in the build.

Thus, I'm surprised by Ken's report, and it looks like something that
we need to figure out what is happening.

Ken's report didn't mention the Asymptote version. As of yesterday's
source tree update, it is 2.64.  Almost all of my builds, except for
the NetBSD systems, have been with Asymptote version 2.62 or 2.63.

----------------------------------------

P.S. I note that gcc-8.4.0 was officially released yesterday, and many
O/S distributions allow installation of multiple major versions of gcc
and clang, without name conflicts.  I typically install all of them on
our test lab machiens, and I've done thousands of builds of gcc and
scores of clang, from source code on our systems.  Thus, that
compiler, if available on Cygwin, would be an alternative.  It is
already in the Ubuntu 20.04 package system, as I found when I updated
one of our 20.04 systems this morning.  Its announcement claimed
over 200 bug fixes compared to gcc-8.3.0.


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- Nelson H. F. Beebe                    Tel: +1 801 581 5254                  -
- University of Utah                    FAX: +1 801 581 4148                  -
- Department of Mathematics, 110 LCB    Internet e-mail: beebe at math.utah.edu  -
- 155 S 1400 E RM 233                       beebe at acm.org  beebe at computer.org -
- Salt Lake City, UT 84112-0090, USA    URL: http://www.math.utah.edu/~beebe/ -
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