On Thu, Jul 16, 2026 at 11:13:03AM +0200, Helmut Grohne wrote: > Hi Adrian, > > On Thu, Jul 16, 2026 at 11:28:09AM +0300, Adrian Bunk wrote: > > Package: debhelper > > Version: 13.32 > > Severity: serious > > X-Debbugs-Cc: Helmut Grohne <[email protected]> > > > > -- Macro: AC_PROG_CXX ([COMPILER-SEARCH-LIST]) > > Determine a C++ compiler to use. > > > > If either the environment variable ‘CXX’ or the environment > > variable ‘CCC’ is set, its value will be taken as the name of a C++ > > compiler. If both are set, ‘CXX’ is preferred. If neither are > > set, search for a C++ compiler under a series of likely names, > > trying ‘g++’ and ‘c++’ first. > > > > > > There are multiple FTBFS because > > AC_PROG_CXX([mpiCC mpixlcxx mpixlcxx_r mpicxx CC]) > > now uses g++ instead of mpiCC. > > > > AC_PROG_CC(clang gcc) > > with a clang build dependency now silently uses gcc instead > > of clang. > > This catches me by surprise. I did rebuild the top1000 packages by > popcon and found exactly one FTBFS (which is fixed now). Given the low > number, we went ahead and then Santiago reached out regarding a few more > FTBFS and we figured the numbers were small enough. > > Surprisingly, none of them were mpicc. Additionally note that many mpicc > users already do have patches and could be applying them. > > Both uses you show are broken for cross compilation, so they need fixes > anyway. When using clang as compiler, the -target option should be > given. > > > This is the kind of behaviour change that is fine in a new compat, > > but IMHO not an appropriate change for older compat levels. > > In an ideal world, I'd agree, but compat levels are so rare and the > failure rate (that I saw) was so low that the compat level did not seem > like a suitable tool. > > I searched current FTBFS bugs and found #1139535. Would you be able to > point to the multiple FTBFSes and also to the clang ones?
I don't have any proven examples for silent changing of the compiler. Regarding FTBFS: I've already fixed #1139537 #1139538 #1139540 The maintainer did a library transition for fixing #1139536 > Helmut cu Adrian
