GUB target_cpu error

[Graham Percival]

building package: linux-x86::lilypond-installer
 *** Stage: download (lilypond-installer, linux-x86)
 *** Stage: compile (lilypond-installer, linux-x86)
Command barfed: /usr/bin/python bin/gib --platform=linux-x86
--branch=guile=
--branch=lilypond=git.sv.gnu.org--lilypond.git-release-unstable
lilypond

Tail of target/linux-x86/log/lilypond-installer.log >>>>>>>>
      File "bin/../gub/commands.py", line 458, in execute
        header_length = len (script % locals ()) + 1
    KeyError: 'target_cpu'
    Command barfed: /usr/bin/python bin/gib --platform=linux-x86
--branch=guile=
--branch=lilypond=git.sv.gnu.org--lilypond.git-release-unstable
lilypond
<<<<<<<< Tail of target/linux-x86/log/lilypond-installer.log


Nothing in lilypond-installer.log immediately jumps out to me as the
cause of the error.

- Graham