GUB and librestrict

[littlesincanada]

Hi,
I'm trying to build Lilypond using GUB.
I'm hitting on a problem in librestrict.

In restrict.c, in the initialize() function, a new c99 keyword 
"restrict" is being used as a variable.
If I rename it, then the source compiles.

However, I get a further failure in the build which I'm not sure how to 
deal with:

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Running dump_file
  ('install', 
'/home/ralph/gub/target/tools/status/librestrict-1.9.a-1.9.a', 'w')
  {'permissions': 420}
 *** Stage: package (librestrict, tools)
invoking false
Command barfed: false
Traceback (most recent call last):
  File "bin/gub", line 233, in exceptional_build
    build (settings, options, files)
  File "bin/gub", line 229, in build
    b.build_source_packages (names)
  File "bin/../gub/buildrunner.py", line 334, in build_source_packages
    self.spec_build (spec_name)
  File "bin/../gub/buildrunner.py", line 262, in spec_build
    deferred_runner.execute_deferred_commands ()
  File "bin/../gub/runner.py", line 167, in execute_deferred_commands
    cmd.execute (self.logger)
  File "bin/../gub/commands.py", line 75, in execute
    ignore_errors=self.ignore_errors)
  File "bin/../gub/loggedos.py", line 93, in system
    raise misc.SystemFailed (m)
SystemFailed: Command barfed: false
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Any ideas how to proceed?

I'm building on Linux Mint 18, x64.

Cheers,
Ralph