The kernel has a BuildDepends on gcc-4.1-hppa64 [hppa] as well as binutils-hppa64 [hppa]. However, linux-ubuntu-modules also needs these tools. I faced this same issue with powerpc. The fix is to add the tools version dependencies to the linux-headers-ABI-FLAVOUR package. This has been done for the upcoming -9 kernel series.
The kernel has a BuildDepends on gcc-4.1-hppa64 [hppa] as well as binutils-hppa64 [hppa]. However, linux-ubuntu- modules also needs these tools. I faced this same issue with powerpc. The fix is to add the tools version dependencies to the linux-headers- ABI-FLAVOUR package. This has been done for the upcoming -9 kernel series.