[tlbuild] asy-2.75 and C++17

[Johannes Hielscher]

Hi,

the asymptote sources, updated to the 2.75 branch since the last
pretest/build season (TL SVN -r61580), had a spectacular build failure
within my usual build setup. The ChangeLog tells that, as of this
summer, they raised the C++ standard level to C++17 (commit
ad6f30f006b1bb277ec7d241c1696073c80a4d34 and [0]).

This smells like a patch of the form:


Index: Master/tlpkg/bin/tl-update-asy
===================================================================
--- Master/tlpkg/bin/tl-update-asy	(revision 61580)
+++ Master/tlpkg/bin/tl-update-asy	(working copy)
@@ -66,7 +66,7 @@
   ./configure --prefix=/tmp/ainst \
     --with-latex=/tmp/ainst/latex --with-context=/tmp/ainst/context \
     --disable-fftw --disable-gl --disable-gsl \
-    --enable-texlive-build CFLAGS=-g CXXFLAGS=-std=c++11 #-ansi
+    --enable-texlive-build CFLAGS=-g CXXFLAGS=-std=c++17 #-ansi
   make
   make check
   make install-prebuilt


and respective changes on the TL website [1].

Builds went fine once I put C++17 in the CXXFLAGS. The GCC in my Debian
Buster (oldstable) environment is just barely capable of that -- there
are other cases where gcc-8.3.0 doesn't quite satisfy the requirements
for C++17 coverage.

Best,
Johannes



[0]
https://github.com/vectorgraphics/asymptote/commit/ad6f30f006b1bb277ec7d241c1696073c80a4d34
[1]
https://tug.org/texlive/build.html#asymptote