vm-pcrisis doesn't compile under Emacs 26.1

[Uday Reddy]

Robert Huff reports (viewmail-info, 3 June 2018)

"emacs" -batch -q -no-site-file -no-init-file -l ./vm-build.el -f
batch-byte-compile vm-pcrisis.el
(file-missing "Cannot open load file" "No such file or directory" "bbdb")
Could not load bbdb.el.  Related functions may not work correctly!

In toplevel form:
vm-pcrisis.el:86:1:Warning: defcustom for `vmpc-conditions' fails to specify
     type
vm-pcrisis.el:86:1:Warning: defcustom for `vmpc-conditions' fails to specify
     type
vm-pcrisis.el:228:35:Warning: make-face called with 2 arguments, but accepts
     only 1
vm-pcrisis.el:235:31:Warning: make-face called with 2 arguments, but accepts
     only 1
vm-pcrisis.el:1217:28:Error: Variable name missing after &optional
gmake[1]: *** [Makefile:114: vm-pcrisis.elc] Error 1
gmake[1]: Leaving directory '/data/vm-8.2.0b/lisp'
gmake: *** [Makefile:37: all] Error 1