[Reproducible-builds] Bug#827155: dpkg-buildflags: reproducible/fixdebugpath doesn't escape build path

[Daniel Kahn Gillmor]

On Sun 2016-06-12 23:25:33 -0400, HW42 wrote:
> as Mattia noticed dpkg-buildflags doesn't escape the build path in the
> -fdebug-prefix-map CC argument when enabling the 'fixdebugpath' option.
>
> What assumptions does dpkg make about the build path? I think there are a
> lot of build scripts which anyway break if the build path contains a
> space.

that seems likely to me -- not just debian packaging scripts either, but
likely upstream build toolchain decisions as well.

> Unfortunately this isn't trivially fixed since the flags are
> concatenated as a string and later exported in different languages
> (shell, Makefile). So if we want to support spaces in buildpaths this
> need to be changed to an array. What do you think?

I think you mean that the flags should be internally stored as an array
inside dpkg-dev instead of a concatenated string.  That sounds right to
me, and a worthwhile change in its own right.

It won't fix any upstream toolchain bugs, of course, and if we start to
vary by having whitespace (or even weirder characters) in paths, we're
likely to see a large number of FTBFS.

fixing dpkg-dev to treat the flags internally as an array seems like a
good first step, though.

     --dkg