I realize this is unlikely to be a helpful report, but something that changed between 3.9.3 and 3.9.4 has caused the build to break on (admittedly a strange platform) ppc64le


I attached the build log (zipped because otherwise it's too big ?)

The live URL is here: https://launchpadlibrarian.net/532585040/buildlog_ubuntu-xenial-ppc64el.python3.9_3.9.4-1+xenial1_BUILDING.txt.gz

Probably the most relevant part of the bug report is this bit, though I'm guessing so I don't really know what is useful and what is not.

```
Preprocessed source stored into /tmp/ccIkITd0.out file, please attach this to your bugreport.
=== BEGIN GCC DUMP ===
// Target: powerpc64le-linux-gnu
// Configured with: ../src/configure -v --with-pkgversion='Ubuntu/IBM 5.4.0-6ubuntu1~16.04.12' --with-bugurl=file:///usr/share/doc/gcc-5/README.Bugs --enable-languages=c,ada,c++,java,go,d,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-5 --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --with-default-libstdcxx-abi=new --enable-gnu-unique-object --disable-libquadmath --enable-plugin --with-system-zlib --disable-browser-plugin --enable-java-awt=gtk --enable-gtk-cairo --with-java-home=/usr/lib/jvm/java-1.5.0-gcj-5-ppc64el/jre --enable-java-home --with-jvm-root-dir=/usr/lib/jvm/java-1.5.0-gcj-5-ppc64el --with-jvm-jar-dir=/usr/lib/jvm-exports/java-1.5.0-gcj-5-ppc64el --with-arch-directory=ppc64le --with-ecj-jar=/usr/share/java/eclipse-ecj.jar --enable-objc-gc --enable-secureplt --with-cpu=power8 --enable-targets=powerpcle-linux --disable-multilib --enable-multiarch --disable-werror --with-long-double-128 --enable-checking=release --build=powerpc64le-linux-gnu --host=powerpc64le-linux-gnu --target=powerpc64le-linux-gnu
// Thread model: posix
// gcc version 5.4.0 20160609 (Ubuntu/IBM 5.4.0-6ubuntu1~16.04.12) 
// 
// ../Python/ceval.c: In function 'is_tstate_valid':
// ../Python/ceval.c:5694:1: internal compiler error: Segmentation fault
//  }
//  ^
// Please submit a full bug report,
// with preprocessed source if appropriate.
// See <file:///usr/share/doc/gcc-5/README.Bugs> for instructions.
```