Hello,

I am the bnf-mode[1] creator.  I am trying to figure out what
happens when I install the mode from the tar archive.  Frankly
speaking, I get a strange error message.

You can see the fresh Makefile I use to create tar archive at GitHub
repo[2].  All I need to create a tar archive is a command
`make package'.  And it seems it works as expected.  However, after
creating the archive, I was failed to install it.  After changing
this line[3] as follows:

diff --git a/Makefile b/Makefile
index c04c01c..d11ac3d 100644
--- a/Makefile
+++ b/Makefile
@@ -122,7 +122,8 @@ package: $(PACKAGE_NAME).tar

 .PHONY: install
 install: $(PACKAGE_NAME).tar
-       $(EMACS) --batch -l package -f package-initialize --eval
"(package-install-file \"$(PWD)/$(PACKAGE_NAME).tar\")"
+       $(EMACS) --batch -l package -f package-initialize --eval \
+               "(let ((debug-on-error t))(package-install-file
\"$(PWD)/$(PACKAGE_NAME).tar\"))"

 .PHONY: help
 help: .title

I got the following debug trace:

$ make install
Parsing tar file...
Parsing tar file...done
Debugger entered--Lisp error: (wrong-type-argument arrayp nil)
  tar--describe-as-link(nil)
  tar--check-descriptor(nil)
  tar-get-file-descriptor("bnf-mode-0.4.3/PaxHeader/PaxHeader-pkg.el")
  package-tar-file-info()
  package-install-from-buffer()
  package-install-file("/home/klay/work/bnf-mode/bnf-mode-0.4.3.tar")
  (let ((debug-on-error t)) (package-install-file
"/home/klay/work/bnf-mode/bnf-mode-0.4.3.tar"))
  eval((let ((debug-on-error t)) (package-install-file
"/home/klay/work/bnf-mode/bnf-mode-0.4.3.tar")))
  command-line-1(("-l" "package" "-f" "package-initialize" "--eval"
"(let ((debug-on-error t))(package-install-file
\"/home/klay/work/bnf-mode/bnf-mode-0.4.3.tar\"))"))
  command-line()
  normal-top-level()

make: *** [Makefile:125: install] Error 255

I have no idea what is PaxHeader/PaxHeader-pkg.el and even stranger
that after inspecting `tar-mode' I found this:

(defun tar-get-file-descriptor (file)
  ;; Used by package.el.
  (let ((desc ()))
    (dolist (hdr tar-parse-info)
      (when (equal file (tar-header-name hdr))
        (setq desc hdr)))
    (tar--check-descriptor desc)
    desc))

As you can see without any validation `desc' was passed to
`tar--check-descriptor` defun.  The `tar--check-descriptor` is just
calls `tar--describe-as-link`:

(defun tar--check-descriptor (descriptor)
  (let ((link-desc (tar--describe-as-link descriptor)))
    (when link-desc
      (error "This is %s, not a real file" link-desc))))

And finally it calls `tar-header-link-type':

(defun tar--describe-as-link (descriptor)
  (let ((link-p (tar-header-link-type descriptor)))
    (if link-p
	(cond ((eq link-p 5) "a directory")
              ((eq link-p 20) "a tar directory header")
              ((eq link-p 28) "a next has longname")
              ((eq link-p 29) "a multivolume-continuation")
              ((eq link-p 35) "a sparse entry")
              ((eq link-p 38) "a volume header")
              ((eq link-p 55) "a pax global extended header")
              ((eq link-p 72) "a pax extended header")
              (t "a link")))))

I will be happy for any help and tips in the right direction.

N.B. My GNU Emacs version is 26.3 on Debian/GNU Linux 10.


[1]: https://elpa.gnu.org/packages/bnf-mode.html
[2]:
https://github.com/sergeyklay/bnf-mode/blob/87c779851e44aab6639cdf2ab699aa9cd41f97c7/Makefile
[3]:
https://github.com/sergeyklay/bnf-mode/blob/87c779851e44aab6639cdf2ab699aa9cd41f97c7/Makefile#L125

--
Serghei