[ESS] Following up, success! [was RE: [R-win] Difficulty installing R packages under Windows 11 / Cygwin]

[Robert Lerche]

> Just to be sure: So all these changes in your patch are guaranteed to *not* change the path / file-paths  anywhere *unless* our emacs & ESS run on an Windows Cygwin  platform?

That is my intention.  Here is a slight "belt and suspenders" update, adding a specific test for Cygwin Emacs. If not, force ess-cygwin-prefix to nil.  I have tested this in my environment.

---

>From 9f64f41c09fed6161de841297239ad74a1c1448d Mon Sep 17 00:00:00 2001
From: Robert Lerche <rlerche using pacificbiosciences.com>
Date: Sun, 7 Jan 2024 10:01:22 -0800
Subject: [PATCH] For compatibility between Cygwin Emacs and R built for
 Windows add prefix to R initialization

---
 lisp/ess-custom.el | 6 ++++++
 lisp/ess-inf.el    | 2 +-
 lisp/ess-r-mode.el | 2 +-
 3 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/lisp/ess-custom.el b/lisp/ess-custom.el
index f631e04d..91d47b0e 100644
--- a/lisp/ess-custom.el
+++ b/lisp/ess-custom.el
@@ -2489,6 +2489,12 @@ Used to store the values for passing on to newly created buffers.")
 (defvar ess-STERM nil
   "Placeholder for dialect-specific STERM.")
 
+(defvar ess-cygwin-prefix
+  (if (not (eq system-type (quote cygwin))) nil
+    (condition-case nil (nth 0 (process-lines "cygpath"  "-m" "/"))
+      (error nil)))
+  "For Windows compatibility, prefix paths passed to R with this")
+
 (make-obsolete-variable 'ess-S-loop-timeout "It is ignored." "ESS 18.10")
 (make-obsolete-variable 'ess-mode-load-hook "It is ignored." "ESS 18.10")
 (make-obsolete-variable 'ess-speedbar-use-p "It is ignored." "ESS 18.10")
diff --git a/lisp/ess-inf.el b/lisp/ess-inf.el
index 9ca3f455..9b611934 100644
--- a/lisp/ess-inf.el
+++ b/lisp/ess-inf.el
@@ -3046,7 +3046,7 @@ NO-ERROR prevents errors when this has not been implemented for
                      path))
              (lpath (if remote
                         (with-parsed-tramp-file-name path v v-localname)
-                      path)))
+                      (concat ess-cygwin-prefix path))))
         (ess-eval-linewise (format ess-setwd-command lpath))
         (ess-set-process-variable 'default-directory
                                   (file-name-as-directory path)))
diff --git a/lisp/ess-r-mode.el b/lisp/ess-r-mode.el
index bd902710..1517d705 100644
--- a/lisp/ess-r-mode.el
+++ b/lisp/ess-r-mode.el
@@ -1572,7 +1572,7 @@ Source the etc/ESSR/.load.R file into the R process. The
 .ess.ESSR.load function sources all of the contents of the
 etc/ESSR/R directory into the ESSR environment and attaches the
 environment to the search path."
-  (let* ((src-dir (expand-file-name "ESSR/R" ess-etc-directory))
+  (let* ((src-dir (concat ess-cygwin-prefix (expand-file-name "ESSR/R" ess-etc-directory)))
          (buf (ess-command (ess-r--load-ESSR-command src-dir))))
     (with-current-buffer buf
       (let ((msg (buffer-string)))
-- 
2.42.1

-----Original Message-----
From: Martin Maechler <maechler using stat.math.ethz.ch> 
Sent: Friday, January 5, 2024 7:58 AM
To: Robert Lerche <rlerche using pacificbiosciences.com>
Cc: Sparapani, Rodney <rsparapa using mcw.edu>; Tomas Kalibera <tomas.kalibera using gmail.com>; ess-help (ess-help using r-project.org) <ess-help using r-project.org>
Subject: Re: [ESS] Following up, success! [was RE: [R-win] Difficulty installing R packages under Windows 11 / Cygwin]

[EXTERNAL MESSAGE] Be mindful when clicking links or attachments

>>>>> Robert Lerche via ESS-help
>>>>>     on Wed, 3 Jan 2024 22:58:00 +0000 writes:

    > Yes and thanks for responding.  That is I think exactly what's needed and I have taken a shot at implementing it.  [I'm glad my previous attached patch got filtered, I was a bit careless.]  Here's a summary of what I've done:
    > ess-custom.el: extract prefix using cygpath, set to nil if error (i.e., no cygpath command indicates not in Cygwin)

Just to be sure: So all these changes in your patch are guaranteed to *not* change the path / file-paths  anywhere
*unless* our emacs & ESS run on an Windows Cygwin  platform?

Martin