Electric Make emits this warning anytime the user specifies an empty value for the --emake-reg-roots option.
To disable registry mirroring, specify --emake-reg-roots=-HKEY_CLASSES_ROOT.
Prior to Accelerator 4.3.0, the interpretation of the --emake-reg-roots command-line option was that it would replace the built-in default registry root setting. A side-effect of this implementation was that the user could completely disable registry mirroring by specifying --emake-reg-roots="" (i.e., an empty string value).
However, the override behavior made it easy for users to unintentionally disable registry mirroring for the default locations when all they wanted was to also mirror some set of keys. This in turn made it possible for users to inadvertently "corrupt" the registry on the cluster by allowing modifications to bleed through to the real registry there.
Therefore, in 4.3.0 the interpretation of the --emake-reg-roots command-line option was changed such that values specified that way are used to augment the built-in default setting, rather than replace it. Therefore, using an empty string to disable registry mirroring no longer works as it did prior to 4.3.0.
An empty value was specified for --emake-reg-roots.
Do not use an empty value for the --emake-reg-roots option. If you want to disable registry mirroring, you must explicitly "uninclude" the portion of the registry that is mirrored by default (HKEY_CLASSES_ROOT). You can do so by specifying that path as an exclude value for the registry root: