+When running @code{process-file} or @code{start-file-process} on a
+remote @code{default-directory}, the default settings in
+@code{process-environment} are not used as it is the case for local
+processes. However, if you need environment variables other than set
+in @code{tramp-remote-process-environment}, you can let-bind them to
+@code{process-environment}. Only those variables will be set then:
+
+@lisp
+(let ((process-environment (cons "HGPLAIN=1" process-environment)))
+ (process-file @dots{}))
+@end lisp
+
+This works only for environment variables which are not set already in
+@code{process-environment}.
+