-spec sanity_check() -> ok | {failed, Failures}
                when
                    Application :: atom(),
                    ApplicationVersion :: string(),
                    MissingRuntimeDependencies ::
                        {missing_runtime_dependencies, ApplicationVersion, [ApplicationVersion]},
                    InvalidApplicationVersion :: {invalid_application_version, ApplicationVersion},
                    InvalidAppFile :: {invalid_app_file, Application},
                    Failure ::
                        MissingRuntimeDependencies | InvalidApplicationVersion | InvalidAppFile,
                    Failures :: [Failure].

Performs a sanity check on the system.

If no issues were found, ok is returned. If issues were found, {failed, Failures} is returned. All failures found will be part of the Failures list. Currently defined Failure elements in the Failures list:

• InvalidAppFile - An application has an invalid .app file. The second element identifies the application which has the invalid .app file.

• InvalidApplicationVersion - An application has an invalid application version. The second element identifies the application version that is invalid.

• MissingRuntimeDependencies - An application is missing runtime dependencies. The second element identifies the application (with version) that has missing dependencies. The third element contains the missing dependencies.

  Note that this check use application versions that are loaded, or will be loaded when used. You might have application versions that satisfies all dependencies installed in the system, but if those are not loaded this check will fail. Of course, the system will also fail when used like this. This can happen when you have multiple branched versions of the same application installed in the system, but there does not exist a boot script identifying the correct application version.

Currently the sanity check is limited to verifying runtime dependencies found in the .app files of all applications. More checks will be introduced in the future. This implies that the return type will change in the future.

Note

An ok return value only means that sanity_check/0 did not find any issues, not that no issues exist.

-spec to_file(FileName) -> ok | {error, Reason}
           when
               FileName :: file:name_all(),
               Reason :: file:posix() | badarg | terminated | system_limit.

Writes miscellaneous system information to file. This information will typically be requested by the Erlang/OTP team at Ericsson AB when reporting an issue.