on the XEmacs website, page:
http://www.xemacs.org/Documentation/packageGuide.html
under the section "Installing by Hand"
There are 2 examples of unpacking the xemacs-base and mule-base that
have a malformed path:
gunzip -c ...../xemacs-base-1.27-pkg.tar.gz | tar xf -
gunzip -c ...../mule-base-1.25-pkg.tar.gz | tar xf -

The "...../" should be replaced with something else.
I'm not exactly sure what to replace them with, but it seems to be meant
to point to the path the file was downloaded to, so maybe replace with a
generic <your download path>?
such as:
gunzip -c <your download path>/xemacs-base-1.27-pkg.tar.gz | tar xf -
gunzip -c <your download path>/mule-base-1.25-pkg.tar.gz | tar xf -