Subject: 30.0.50; Error in TRAMP due to variable aliasing

From: Eshel Yaron <[email-masked]>
Date: Tue, 21 Mar 2023 14:00:23 +0200

The recent rename of tramp-use-ssh-controlmaster-options in commit
1c39347d585 seems to cause some problems, namely Emacs now fails with an
error when trying to load tramp-sh (which happens automatically in some
TRAMP flows) if tramp is already loaded and compilation-mode-hook ran.
To reproduce:

1. emacs -Q
2. (require 'tramp)
   This further requires tramp-integration which adds a function
   called tramp-compile-disable-ssh-controlmaster-options to
   compilation-mode-hook
3. Do something that runs compilation-mode-hook, e.g. M-x compile with
   some dummy compilation command like "true".
4. Try to load tramp-sh with e.g. (require 'tramp-sh)
   Emacs fails with an error saying:
   "Don’t know how to make a buffer-local variable an alias:
   tramp-use-connection-share".
   AFAIU This happens because at this point tramp-use-connection-share is
   already a localized symbol and tramp-sh tries to call defvaralias on it.

Thanks,
Eshel

In GNU Emacs 30.0.50 (build 25, x86_64-apple-darwin22.3.0, NS
 appkit-2299.40 Version 13.2.1 (Build 22D68)) of 2023-03-21 built on
 esmac.local
Repository revision: 42fba8f36b19536964d6deb6a34f3fd1c02b43dd
Repository branch: master
Windowing system distributor 'Apple', version 10.3.2299
System Description:  macOS 13.2.1

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