bug#45287: 28.0.50; byte-compile-file results in error with commit fe50a8b9ba or later on master

[Yasuhiro KIMURA]

commit fe50a8b9ba
Author: Philipp Stephani <phst@google.com>
Date:   Sun Dec 13 17:13:50 2020 +0100

    Byte compilation: handle case where the output file is a mountpoint.

    See Bug#44631.  While testing for a readonly output directory has
    slightly different semantics, in practice they should cover cases
    where Emacs is sandboxed and can only write to the destination file,
    not its directory.

    * lisp/emacs-lisp/bytecomp.el (byte-compile-file): Handle the case
    where the output directory is not writable.

    * test/lisp/emacs-lisp/bytecomp-tests.el
    (bytecomp-tests--not-writable-directory)
    (bytecomp-tests--dest-mountpoint): New unit tests.

With this commit or later on master,

https://github.com/yasuhirokimura/tamago/tree/fix_build_after_the_removal_of_make_coding_system

build of this application fails as following.

if test "emacs" != "no"; then \
  am__dir=. am__subdir_includes=''; \
  case cannarpc.elc in */*) \
    am__dir=`echo 'cannarpc.elc' | sed 's,/[^/]*$,,'`; \
    am__subdir_includes="-L $am__dir -L ./$am__dir"; \
  esac; \
  test -d "$am__dir" || /usr/bin/mkdir -p "$am__dir" || exit 1; \
  emacs --batch \
    -q -no-site-file -no-init-file --eval="(setq load-path (append (list 
(expand-file-name \"..\")) load-path))" --eval="(load \"docomp.el\")"  \
    $am__subdir_includes -L . -L . \
    --eval "(defun byte-compile-dest-file (f) \"cannarpc.elc\")" \
    --eval "(unless (byte-compile-file \"cannarpc.el\") (kill-emacs 1))"; \
else :; fi
Loading c:/Users/yasu/Work/Emacs/master/tamago/docomp.el (source)...
Package cl is deprecated
Debugger entered--Lisp error: (wrong-type-argument stringp nil)
  file-writable-p(nil)
  byte-compile-file("cannarpc.el")
  (if (byte-compile-file "cannarpc.el") nil (kill-emacs 1))
  (unless (byte-compile-file "cannarpc.el") (kill-emacs 1))
  eval((unless (byte-compile-file "cannarpc.el") (kill-emacs 1)) t)
  command-line-1(("--eval=(setq load-path (append (list (expand-file-..." 
"--eval=(load \"docomp.el\")" "-L" "." "-L" "." "--eval" "(defun 
byte-compile-dest-file (f) \"cannarpc.elc\")" "--eval" "(unless 
(byte-compile-file \"cannarpc.el\") (kill-em..."))
  command-line()
  normal-top-level()

make[2]: *** [Makefile:315: cannarpc.elc] Error 127
make[2]: Leaving directory '/c/Users/yasu/Work/Emacs/master/tamago/egg'
make[1]: *** [Makefile:489: all-recursive] Error 1
make[1]: Leaving directory '/c/Users/yasu/Work/Emacs/master/tamago'
make: *** [Makefile:361: all] Error 2


In GNU Emacs 28.0.50 (build 1, x86_64-w64-mingw32)
 of 2020-12-17 built on ROLLING
Repository revision: 51698f77dd6356049fcacdb01ebe80cfe4c67272
Repository branch: HEAD
Windowing system distributor 'Microsoft Corp.', version 10.0.19042
System Description: Microsoft Windows 10 Enterprise (v10.0.2009.19042.685)

Configured using:
 'configure --prefix=/c/Emacs-master --without-dbus'

Configured features:
XPM JPEG TIFF GIF PNG RSVG SOUND NOTIFY W32NOTIFY ACL GNUTLS LIBXML2
HARFBUZZ ZLIB TOOLKIT_SCROLL_BARS MODULES THREADS JSON PDUMPER

Important settings:
  value of $LANG: JPN
  locale-coding-system: cp932

Major mode: Fundamental

Minor modes in effect:
  magit-auto-revert-mode: t
  global-git-commit-mode: t
  shell-dirtrack-mode: t
  tooltip-mode: t
  global-eldoc-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  tool-bar-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  blink-cursor-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  buffer-read-only: t
  line-number-mode: t
  transient-mark-mode: t

Load-path shadows:
c:/Emacs-master/share/emacs/site-lisp/flim/sasl hides 
c:/Emacs-master/share/emacs/28.0.50/lisp/net/sasl

Features:
(shadow pp mew-varsx mew-win32 mew-w3m w3m doc-view jka-compr
image-mode exif timezone w3m-hist w3m-fb bookmark-w3m w3m-ems wid-edit
w3m-favicon w3m-image tab-line w3m-proc w3m-util mew-auth mew-config
mew-imap2 mew-imap mew-nntp2 mew-nntp mew-pop mew-smtp mew-ssl mew-ssh
mew-net mew-highlight mew-sort mew-fib mew-ext mew-refile mew-demo
mew-attach mew-draft mew-message mew-thread mew-virtual mew-summary4
mew-summary3 mew-summary2 mew-summary mew-search mew-pick mew-passwd
mew-scan mew-syntax mew-bq mew-smime mew-pgp mew-header mew-exec
mew-mark mew-mime mew-edit mew-decode mew-encode mew-cache mew-minibuf
mew-complete mew-addrbook mew-local mew-vars3 mew-vars2 mew-vars
mew-env mew-lang-jp mew-mule3 mew-mule mew-gemacs mew-key mew-func
mew-blvs mew-const mew emacsbug sendmail magit-version edmacro kmacro
yaml-mode mime-setup mail-mime-setup alist semi-setup advice path-util
apel-ver product semi-def rng-nxml rng-valid rng-loc rng-uri rng-parse
nxml-parse rng-match rng-dt rng-util rng-pttrn nxml-ns nxml-mode
nxml-outln nxml-rap sgml-mode dom nxml-util nxml-enc xmltok
magit-submodule magit-obsolete magit-blame magit-stash magit-reflog
magit-bisect magit-push magit-pull magit-fetch magit-clone
magit-remote magit-commit magit-sequence magit-notes magit-worktree
magit-tag magit-merge magit-branch magit-reset magit-files magit-refs
magit-status magit package browse-url url url-proxy url-privacy
url-expand url-methods url-history url-cookie url-domsuf url-util
mailcap url-handlers url-parse url-vars magit-repos magit-apply
magit-wip magit-log which-func imenu magit-diff smerge-mode diff
diff-mode magit-core magit-autorevert autorevert filenotify
magit-margin magit-transient magit-process magit-mode git-commit
transient format-spec magit-git magit-section magit-utils crm log-edit
easy-mmode message rmc puny dired dired-loaddefs rfc822 mml mml-sec
epa derived epg epg-config gnus-util rmail rmail-loaddefs auth-source
eieio eieio-core cl-macs eieio-loaddefs password-cache json map
text-property-search time-date mm-decode mm-bodies mm-encode
mail-parse rfc2231 rfc2047 rfc2045 mm-util ietf-drums mail-prsvr
mailabbrev mail-utils gmm-utils mailheader pcvs-util add-log
with-editor cl-extra help-mode seq byte-opt bytecomp byte-compile
cconv cl-seq shell pcomplete comint ansi-color ring server subr-x dash
gv cl-loaddefs cl-lib gitignore-mode gitconfig-mode conf-mode rx
gitattributes-mode thingatpt easymenu japan-util iso-transl tooltip
eldoc electric uniquify ediff-hook vc-hooks lisp-float-type mwheel
dos-w32 ls-lisp disp-table term/w32-win w32-win w32-vars
term/common-win tool-bar dnd fontset image regexp-opt fringe
tabulated-list replace newcomment text-mode elisp-mode lisp-mode
prog-mode register page tab-bar menu-bar rfn-eshadow isearch timer
select scroll-bar mouse jit-lock font-lock syntax facemenu font-core
term/tty-colors frame minibuffer cl-generic cham georgian utf-8-lang
misc-lang vietnamese tibetan thai tai-viet lao korean japanese
eucjp-ms cp51932 hebrew greek romanian slovak czech european ethiopic
indian cyrillic chinese composite charscript charprop case-table
epa-hook jka-cmpr-hook help simple abbrev obarray cl-preloaded nadvice
button loaddefs faces cus-face macroexp files window text-properties
overlay sha1 md5 base64 format env code-pages mule custom widget
hashtable-print-readable backquote threads w32notify w32 multi-tty
make-network-process emacs)

Memory information:
((conses 16 208066 6100)
 (symbols 48 22414 33)
 (strings 32 73731 1940)
 (string-bytes 1 2181085)
 (vectors 16 35974)
 (vector-slots 8 527467 17880)
 (floats 8 124 187)
 (intervals 56 574 116)
 (buffers 984 12))