I have a requirements.txt file with the following:

my-package[extra]~=1.0
my-sub-package~=1.1

When I run python -m piptools compile, the extra requirement [extra] gets lost in the list of via requirements under my-sub-package:

my-package[extra]==1.0.0
    # via -r requirements.txt
my-sub-package==1.1.1
    # via
    #   -r requirements.txt
    #   my-package

I need the extra requirements to remain in the comments. We're parsing the output file of pip-compile that's breaking because the [extra] requirement is gone from the comments.