Source: gcc-6 Package: gnat-6 Version: 6.3.0-4 Followup-For: Bug #839209 Hello.
gcc Depends: gcc-6, and they provide the following /usr/bin symlinks. gcc : gcc -> gcc-6 gcc : ARCH-gcc -> gcc-6 gcc-6 : gcc-6 -> ARCH-gcc-6 For gnat-6 (the gnat package has a different role than the gcc package): gnat-6 : gnat -> gnat-6 gnat-6 : ARCH-gnat -> ARCH-gnat-6 gnat-6 : gnat-6 -> ARCH-gnat-6 By the way, the comparison suggests that gcc : ARCH-gcc -> ARCH-gcc-6 would probably be more consistent than gcc : ARCH-gcc -> gcc-6 -> ARCH-gcc-6 I may check other compilers and report a separate wishlist bug if this seams a good idea. The gnat-6 package also provides a gnatgcc symlink, so that gnat-6 may coexist with a more recent default gcc, say gcc(=7). Code produced by /usr/bin/gnat->gnat-6 can be mixed with code sharing the same ABI, from /usr/bin/gnatgcc->gcc-6, but not from the default C compiler /usr/bin/gcc->gcc-7. As a consequence, - /usr/bin/(ARCH-)?gnatgcc-6 symlinks would be of no use. If the right version is known, (ARCH-)?gcc-6 can be called directly. - gnat-6 Depends: gcc-6, but has no reason to Depend: gcc. Users of gnat-6 may have good reasons not to install gcc-7. Currently, gnat-6 : ARCH-gnatgcc -> ARCH-gcc-6 gnat-6 : gnatgcc -> ARCH-gcc The latter symlink is broken when the gcc package is not installed, and worst, may refer to the wrong ABI when it is. Letting /usr/bin/gnatgcc target ARCH-gcc-6 probably solves the issue. This bug causes no FTBFS because gcc is listed in build-essential, but source packages mixing Ada and C sources will silently start to produce faulty binary packages when gcc-7 becomes the default. Most Ada autopkgtests already fail because gprbuild relies on gnatgcc to detect an Ada compiler (see #838483). This justifies a "serious" severity in my opinion.