tree e9cac3d6618be46ba44fbf881ae2c32c7ac93aa3
parent a74ece26fabaa2c9d6cb45dcc3b0bd56423b56ec
author Joel Stanley <joel@jms.id.au> 1486947710 +1030
committer Joel Stanley <joel@jms.id.au> 1486947845 +1030

op-build-env: warn when user forgets buildroot submodule

If you don't have the buildroot submodule present, the build fails in a
confusing way:

  op-build witherspoon_defconfig
  make: Entering directory '/home/benh/op-build/buildroot'
  make: *** No rule to make target 'witherspoon_defconfig'.  Stop.
  make: Leaving directory '/home/benh/op-build/buildroot

This change gives the user a better chance:

  $ . op-build-env
  Please make sure you've checked out the buildroot submodule
    git submodule init && git submodule update

Signed-off-by: Joel Stanley <joel@jms.id.au>