Bug#926483: FTBFS: utils/blkmapd/device-discovery.c:156: undefined reference to `major'
major(dev) is defined as a macro in <sys/sysmacros.h> which is provided by libc6-dev. I don't see that listed as an explicit build dependency, so it's conceivable that it might be present in some build environments but not in others. The configure script tests for it, potentially leading to #define MAJOR_IN_SYSMACROS 1 (and/or to #define MAJOR_IN_MKDEV 1, but <sys/mkdev.h> seems associated with ZFS and the Solaris Porting Layer only).
Would it be wrong to add an explicit build dependency on libc6-dev? Does it actually cure the FTBFS?