Hi there! I pushed a variant of the patch proposed earlier, adding a similar workaround to ‘Java_java_io_VMFile_exists’ and ‘Java_java_io_VMFile_isDirectory’: https://git.savannah.gnu.org/cgit/guix.git/commit/?h=core-updates-frozen&id=7f50543d55b20cd528b28d7e15f1bb81001a8da9 With this, I can build ‘ant-bootstrap’ just fine. \o/ Next up: icedtea 1.13.13 chokes on obscure C++ issues: --8<---------------cut here---------------start------------->8--- In file included from /tmp/guix-build-icedtea-1.13.13.drv-0/icedtea6-1.13.13/openjdk-ecj/hotspot/src/share/vm/asm/assembler.hpp:29, from /tmp/guix-build-icedtea-1.13.13.drv-0/icedtea6-1.13.13/openjdk-ecj/hotspot/src/share/vm/precompiled/precompiled.hpp:29: /tmp/guix-build-icedtea-1.13.13.drv-0/icedtea6-1.13.13/openjdk-ecj/hotspot/src/share/vm/code/relocInfo.hpp:374:27: error: friend declaration of ‘relocInfo prefix_relocInfo(int)’ specifies default arguments and isn’t a definition [-fpermissive] 374 | inline friend relocInfo prefix_relocInfo(int datalen = 0); | ^~~~~~~~~~~~~~~~ In file included from /tmp/guix-build-icedtea-1.13.13.drv-0/icedtea6-1.13.13/openjdk-ecj/hotspot/src/share/vm/asm/assembler.hpp:29, from /tmp/guix-build-icedtea-1.13.13.drv-0/icedtea6-1.13.13/openjdk-ecj/hotspot/src/share/vm/precompiled/precompiled.hpp:29: /tmp/guix-build-icedtea-1.13.13.drv-0/icedtea6-1.13.13/openjdk-ecj/hotspot/src/share/vm/code/relocInfo.hpp:472:18: error: friend declaration of ‘relocInfo prefix_relocInfo(int)’ specifies default arguments and isn’t the only declaration [-fpermissive] 472 | inline relocInfo prefix_relocInfo(int datalen) { | ^~~~~~~~~~~~~~~~ --8<---------------cut here---------------end--------------->8--- Anyway, we’re making progress! Ludo’.