The dependency graph of the requirements is as follows:

dev         prod
+ +          +
| +->common<-+
v
mypy,docs

Of the files, only dev, prod, and mypy have been used in the install scripts directly. The rest are implicit dependencies.

common and dev are locked.

Steps to update a lock file, e.g. to update ipython from 5.3.0 to 6.0.0 in common.in and propagate it to dev.txt and prod.txt: 0. Replace ipython==5.4.1 with ipython==6.0.0 in common.in.

1. Run ./tools/update-locked-requirements.
2. Increase PROVISION_VERSION in version.py.
3. Run ./tools/provision to install the new deps and test them.
4. Commit your changes.