debian/rules and /usr/share/dpkg/buildflags.mk:38: *** missing separator

[Ross Vandegrift <ross@kallisti.us>]

Hello,

#858563 reports that debian/rules cannot be invoked directly on efl.
The suggested fix is to add "include /usr/share/dpkg/default.mk".

That doesn't work, I'm struggling to understand why:

$ gbp buildpackage  --git-builder=sbuild --git-arch=amd64 --git-dist=experimental --git-ignore-new
...
make[1]: Entering directory '/home/ross/src/e/efl'
dh_clean
find -name '*.luac' -exec rm {} \;
find -name '*shader*.x' -exec rm {} \;
make[1]: Leaving directory '/home/ross/src/e/efl'
/usr/share/dpkg/buildflags.mk:38: *** missing separator.  Stop.
E: Failed to clean source directory /home/ross/src/e/efl (/home/ross/src/e/efl_1.19.0-1.dsc)
gbp:error: 'sbuild' failed: it exited with 1


I tried the exampel from dpkg-buildflags(1) but that has the same issue.
The alternate suggestion iin #858563 to include architecture.mk works,
but I'd like to understand what's going on.

I figured I had a mistake in debian/rules.  But make still dies with
this error if I comment out all of debian/rules but the default dh rule.

Thanks,
Ross