Bug#774129: should dpkg-buildpackage set the cross build profile automatically?
Some packages need extra Build-Depends when they are cross compiled.
Here are some examples:
* src:guile-2.0 needs guile-2.0 to cross-build
* src:glib2.0 needs libglib2.0-dev:any to cross-build
* src:autogen needs autogen to cross-build
* src:flex runs help2man and an easy way to do that is to use the build
* src:bison also runs help2man and can benefit from build arch bison
A way to address this need is to use the "cross" build profile. Now I
am wondering whether dpkg-buildpackage should set the cross build
profile automatically. The logic for doing so is as simple as: if the
host architecture differs from the build architecture, enable that
Johannes Schauer pointed out that since there currently is no way to
disable automatically enabled profiles, this can hamper debugging.
A side effect of this change is that cross built packages would be
reliably recognizable by looking at their Built-For-Profiles header.
Arguably, adding a new header to record the build architecture would be
a better facility.
Also apt (and every other tool that installs Build-Depends) would need
to set this profile automatically.
If dpkg is not the place to add this facility, the place that invokes
dpkg-buildpackage needs to enable this profile explicitly. That probably
means that sbuild needs to do this.