Comment 0 for bug 1187722

This causes an FTBFS in golang. See: https://launchpad.net/ubuntu/+source/golang/2:1.1-1/+build/4578681

Affected: dpkg 1.16.10ubuntu1
Not affected: dpkg 1.16.10

I believe the difference is caused by Steve McIntyre's armhf detection patch
applied in the Ubuntu dpkg delta.

For convenience, I attach a golang armhf binary which dpkg-shlibdeps doesn't work with. The error is:

dpkg-shlibdeps: error: couldn't find library libpthread.so.0 needed by /tmp/go (ELF format: 'elf32-littlearm-sfabi'; RPATH: '')
dpkg-shlibdeps: error: couldn't find library libc.so.6 needed by /tmp/go (ELF format: 'elf32-littlearm-sfabi'; RPATH: '')
dpkg-shlibdeps: error: couldn't find library ld-linux-armhf.so.3 needed by /tmp/go (ELF format: 'elf32-littlearm-sfabi'; RPATH: '')
dpkg-shlibdeps: warning: binaries to analyze should already be installed in their package's directory
dpkg-shlibdeps: error: cannot continue due to the errors listed above
Note: libraries are not searched in other binary packages that do not have any shlibs or symbols file.
To help dpkg-shlibdeps find private libraries, you might need to set LD_LIBRARY_PATH.

The cause is that "readelf -A -- /tmp/go" doesn't produce any output. The
arm-specific handling in Dpkg::Shlibs::Objdump then errnoneously decides that
this means that the binary is "elf32-littlearm-sfabi", which mismatches its
dependencies. This causes it to fail, when in fact there is no problem with
the binary's linkage or execution.

Is it a requirement for armhf binaries to have Tag_ABI_VFP_args? I'm not sure
whether the ABI spec actually requires this in order for a binary to be
expected to dynamically link against a libc that does declare the tag. Even if
so, does it make sense for dpkg to handle this condition more gracefully?

Is there a spec which defines a requirement to have Tag_ABI_VFP_args set, so
that we may refer golang upstream to it for a fix? Or is golang producing valid
binaries and dpkg-shlibdeps is buggy?