Compiles appup source into the application's ebin directory.
Configure the source with the :appup project key, relative to mix.exs:
def project do
[
appup: "appup.exs",
compilers: Mix.compilers() ++ [:appup]
]
endThe source is evaluated for its value and must not introduce top-level
bindings. The compiler writes <app>.appup beside the application's BEAM
files on every build.
A configured but missing source is a compilation error. When the source or
project key is removed, the compiler deletes stale output. To disable appups
for one environment, keep the compiler registered and set :appup to nil.