You can now do:
bash <(curl http://hydra-server/build/1238757/reproduce)
to download and execute a script that reproduces a Hydra build
locally. This script fetches all inputs (e.g. Git repositories) and
then invokes nix-build.
The downloaded sources are stored in /tmp/build-<buildid> and reused
between invocations of the script.
Any additional command line options are passed to nix-build. So
bash <(curl http://hydra-server/build/1238757/reproduce) --run-env
will drop you in a shell where you can interactively hack on the
build, e.g.
$ source $stdenv/setup
$ set +e
$ unpackPhase
$ cd $sourceRoot
$ configurePhase
$ emacs foo.c &
$ make
and so on.
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