Source: mupdf Version: 1.11+ds1-1mupdf no longer builds the *-dbgsym packages. I suspect it's because the upstream build system strips the binaries. In the build log I see:
cc -Wl,-z,relro -Wl,-z,now -Wl,--gc-sections -Wl,-s -o build/release/mutool build/release/source/tools/mutool.o ... (Note the "-Wl,-s" option.) -- Jakub Wilk

