Previously, when `NgPackagesInstaller` needed to install the local
Angular packages to a project, it assumed the `dist/packages-dist/`
would exist and contain up-to-date built packages. I.e. it was up to the
user to have built the packages first (by running the appropriate
script).
However, many people not familiar with the `aio/` infrastructure assumed
that `yarn build-local` or `yarn build-with-ivy` would take care of all
the necessary steps.
To avoid getting confusing errors (or worse yet, using outdated local
packages), `NgPackagesInstaller` now has an option to build the packages
before using them.
One caveat is that the build script does not currently work on Windows,
so a warning is printed instead, letting the user know they need to
(somehow) take care of it themselves.
NOTE 1: Since the build script is using bazel, running it should not be
expensive if the directory is up-to-date (i.e. no changes have
been made to source code after the last build).
NOTE 2: This commit adds support for `--build-packages`, but does not
change the default behavior (not building the packages). It will
be turned on in a subsequent commit.
PR Close#31985
18aa173d39