These scripts are originally from the cabal-install repo with a few small tweaks.
This utility allows you to build hadrian without cabal-install, which can be useful for packagers. If you are a developer then build hadrian using cabal-install.
If you want to bootstrap with ghc-8.10.5 then run the ./bootstrap script with the
plan-bootstrap-8_10_5.json file.
bootstrap.py -w /path/to-ghc -d plan-bootstrap-8_10_5.json
This default option will download the dependencies using the network.
The result of the bootstrap script will be a hadrian binary in
_build/bin/hadrian.
Alternatively, you can provide a tarball with the source of any dependencies.
bootstrap.py -w /path/to-ghc -s sources-tarball.tar.gz
Which dependencies you need can be queried using the list-sources option.
bootstrap.py -w /path/to-ghc -d plan-bootstrap-8_10_5.json list-sources
This produces fetch_plan.json which tells you where to get each source from.
You can instruct the script to create the tarball using the fetch option.
bootstrap.py -w /path/to-ghc -d plan-bootstrap-8_10_5.json fetch -o sources-tarball
There is a script (using nix) which can be used to generate the bootstrap plans for the range of supported GHC versions using nix.
generate_bootstrap_plans
Otherwise you can run the commands in ./generate_bootstrap_plans directly.