In some cases (Travis), sources and build caches may be moved around in-between
builds, and we can't necessarily trust that everything is still intact.
This introduces pre-build checks that verify against stashed checksums.
Note that this will cause all sources to be re-downloaded, since cached sources
weren't trustworthy before this.
Since the last commit will force rebuilds of all depends, take the opportunity
to clean up a few other things that would trigger rebuilds as well.
- Move source stamps to the sources dir so that SOURCES_PATH is respected for
"make download".
- Only print "fetching..." when actually downloading a file.
- Avoid using non-deterministic paths for the recipe hash (patch location).
This should ensure that all builders get the same resulting build-ids.
- Use a per-package source paths. This will allow for removing old source files
in the future.
- Use a host-agnostic path for downloads which gets cleaned up properly.
We're not ready to switch to a static qt5 for Linux yet due to missing plugin
support. This adds a recipe for building a shared qt4 that we build and link
against, but don't distribute.
make USE_LINUX_STATIC_QT5=1 can be used to build static qt5 as before.
