I ran toggle-debug-on-quit and used C-g to give me a backtrace.
Which allowed me to provide the name of the offending function and argument in my original note. I had tried setting tramp-verbose to 10, when searching for the problem, however I didn't find the output very useful which is why I tried to narrow down the issue before reporting to the list.
Luckily mentioning that I was using tramp to a FreeBSD host, triggered a very helpful response.
Atanu.
Debugger entered--Lisp error: (quit)
accept-process-output(#<process *tramp/scp k1*> 1 nil t)
byte-code("\305\206\306\307\310#\211\nB\311\216\312 \f \205\313$+\207" [timeout -with-timeout-timer- with-timeout-timers proc timeout-msecs run-with-timer 1 nil #[nil "\300\301\211\"\207" [throw timeout] 3] ((cancel-timer -with-timeout-timer-)) accept-process-output t] 6)
tramp-accept-process-output(#<process *tramp/scp k1*> 1)
tramp-wait-for-regexp(#<process *tramp/scp k1*> nil "\\(^\\|\\)[^#$\n]*///3b5bdf7e407fc5da0f041475bdcd0ec6#\\$
?$")
tramp-wait-for-output(#<process *tramp/scp k1*>)
tramp-send-command(["scp" nil "k1" "/home/atanu/foo/foo" nil] "tramp_vc_registered_read_file_names <<'b579980d17f5b410fd07febc79651e73'\n/home/atanu/foo/RCS/foo\\,v\n/home/atanu/foo/foo\\,v\n/home/atanu/foo/RCS/foo\n/home/atanu/foo/CVS/Entries\n/home/atanu/foo/foo/.svn\n/home/atanu/foo/.svn\n/home/atanu/.svn\n/home/.svn\n/.svn\n/home/atanu/foo/SCCS/s.foo\n/home/atanu/foo/s.foo\n/home/atanu/foo/foo/.bzr/checkout/format\n/home/atanu/foo/.bzr/checkout/format\n/home/atanu/.bzr/checkout/format\n/home/.bzr/checkout/format\n/.bzr/checkout/format\n/home/atanu/foo/foo/.git\n/home/atanu/foo/.git\n/home/atanu/.git\n/home/.git\n/.git\n/home/atanu/foo/foo/.hg\n/home/atanu/foo/.hg\n/home/atanu/.hg\n/home/.hg\n/.hg\n/home/atanu/foo/foo/_MTN/format\n/home/atanu/foo/_MTN/format\n/home/atanu/_MTN/format\n/home/_MTN/format\n/_MTN/format\n/home/atanu/foo/foo/\\{arch\\}/\\=tagging-method\n/home/atanu/foo/\\{arch\\}/\\=tagging-method\n/home/atanu/\\{arch\\}/\\=tagging-method\n/home/\\{arch\\}/\\=tagging-method\n/\\{arch\\}/\\=tagging-method\nb579980d17f5b410fd07febc79651e73\n")
byte-code("\303\304\305 \306\307\n\310# $\"\210r\311!q\210eb\210\312p!)\207" [v tramp-end-of-heredoc tramp-vc-registered-file-names tramp-send-command format "tramp_vc_registered_read_file_names <<'%s'\n%s\n%s\n" mapconcat tramp-shell-quote-argument "\n" tramp-get-connection-buffer read] 9)
tramp-sh-handle-vc-registered("/scp:k1:/home/atanu/foo/foo")
apply(tramp-sh-handle-vc-registered "/scp:k1:/home/atanu/foo/foo")
tramp-sh-file-name-handler(vc-registered "/scp:k1:/home/atanu/foo/foo")
apply(tramp-sh-file-name-handler vc-registered "/scp:k1:/home/atanu/foo/foo")
byte-code("\300\301\215\207" [suppress (apply foreign operation args)] 2)
byte-code("K\306\211<address@hidden"address@hidden \202\221\320\321!\211 \205D\322\f!)\203P\323\320\321!!\202\221\320\324!\211 \205[\322\f!)\203g\323\320\324!!\202\221\320\325!\211 \205r\322\f!)\203~\323\320\325!!\202\221\326\327!\203\212\323\327!\202\221\330\331!\210\323\332!)address@hidden)\336\337\215\211\336=\203\314+\340\341\342,C-\"C . / 0 1\306\343\344\217,\210\345,-\"\202 \346=\203\377\306 2+\347\350\342,C-\"C . / 0 1\306\343\344\217,\210\351+\352\"\210\345,-\")\202 *\207" [foreign result sf file-name-handler-alist d default-directory nil autoload boundp temporary-file-directory eval standard-value fboundp temp-directory subrp functionp getenv "TEMP" file-directory-p file-name-as-directory "TMP" "TMPDIR" file-exists-p "c:/temp" message "Neither `temporary-file-directory' nor `temp-directory' is defined -- using /tmp." "/tmp" load noerror nomessage non-essential (byte-code "\300\301\215\207" [suppress (apply foreign operation args)] 2) 5 "Non-essential received in operation %s" append (byte-code " X\205g\306 \307\216 \203;\310X\203;\311\312\313U\203!\314\2026\315U\203+\314\2026\316U\2035\317\2026\320\fP
#\210 \321Y\205f\322!\203S\313\323\324\325#)\326!\205f\311\327\330\331\"\fP
$*\207" [level tramp-verbose save-match-data-internal tramp-message-show-message fmt-string arguments match-data ((byte-code "\301\302\"\207" [save-match-data-internal set-match-data evaporate] 3)) 3 apply message 0 "" 1 2 "Warning: " "Tramp: " 4 processp tramp-get-connection-property "vector" nil vectorp tramp-debug-message format "(%d) # " vec-or-proc] 6) ((error)) tramp-run-real-handler suppress 1 "Suppress received in operation %s" tramp-cleanup-connection t v operation args arguments fmt-string level vec-or-proc ...] 7)
tramp-file-name-handler(vc-registered "/scp:k1:/home/atanu/foo/foo")
vc-registered("/scp:k1:/home/atanu/foo/foo")
vc-backend("/scp:k1:/home/atanu/foo/foo")
#[nil "\203\306 \205\272\307 !\210\310\311\312\306\313$\210\306\314\315\316\217\211\2036\312 \n\"\210 \204/\317\304!\210\313\320\n\321\"\202\271
\205=\322
!\211 $\205O $\232?\205O\323$!\211 %\204Y\306\202\270&\306=\203h\324\325%\"\202\270&\326=\203\221'\204\221\327 \203\207\330 A\204\207\331 (=\204\221\332\333\334 !!!\203\236\335 \210\324\336 \"\210\337 \202\270\340\341\342%\"!\203\265\335 \210\324\336 \"\210\337 \202\270\324\343!*)\207" [vc-mode buffer-file-name backend vc-make-backup-files backup-inhibited buffer-file-truename nil vc-file-clearprops add-hook vc-mode-line-hook vc-mode-line t err (vc-backend buffer-file-name) (((debug error) (message "Error: %S" err) nil)) make-local-variable vc-call-backend find-file-hook expand-file-name vc-backend message "Warning: symbolic link to %s-controlled source file" ask daemonp frame-list selected-frame get-file-buffer abbreviate-file-name file-chase-links vc-follow-link "Followed link to %s" vc-find-file-hook yes-or-no-p format "Symbolic link to %s-controlled source file; follow link? " "Warning: editing through the link bypasses version control" truename link-type vc-follow-symlinks noninteractive terminal-frame] 6 2577833]()
funcall(#[nil "\203\306 \205\272\307 !\210\310\311\312\306\313$\210\306\314\315\316\217\211\2036\312 \n\"\210 \204/\317\304!\210\313\320\n\321\"\202\271
\205=\322
!\211 $\205O $\232?\205O\323$!\211 %\204Y\306\202\270&\306=\203h\324\325%\"\202\270&\326=\203\221'\204\221\327 \203\207\330 A\204\207\331 (=\204\221\332\333\334 !!!\203\236\335 \210\324\336 \"\210\337 \202\270\340\341\342%\"!\203\265\335 \210\324\336 \"\210\337 \202\270\324\343!*)\207" [vc-mode buffer-file-name backend vc-make-backup-files backup-inhibited buffer-file-truename nil vc-file-clearprops add-hook vc-mode-line-hook vc-mode-line t err (vc-backend buffer-file-name) (((debug error) (message "Error: %S" err) nil)) make-local-variable vc-call-backend find-file-hook expand-file-name vc-backend message "Warning: symbolic link to %s-controlled source file" ask daemonp frame-list selected-frame get-file-buffer abbreviate-file-name file-chase-links vc-follow-link "Followed link to %s" vc-find-file-hook yes-or-no-p format "Symbolic link to %s-controlled source file; follow link? " "Warning: editing through the link bypasses version control" truename link-type vc-follow-symlinks noninteractive terminal-frame] 6 2577833])
(with-no-warnings (funcall ad--addoit-function))
(setq ad-return-value (with-no-warnings (funcall ad--addoit-function)))
(let (ad-return-value) (setq ad-return-value (with-no-warnings (funcall ad--addoit-function))) (when (svn-status-in-vc-mode\?) (svn-status-update-modeline)) ad-return-value)
ad-Advice-vc-find-file-hook(#[nil "\203\306 \205\272\307 !\210\310\311\312\306\313$\210\306\314\315\316\217\211\2036\312 \n\"\210 \204/\317\304!\210\313\320\n\321\"\202\271
\205=\322
!\211 $\205O $\232?\205O\323$!\211 %\204Y\306\202\270&\306=\203h\324\325%\"\202\270&\326=\203\221'\204\221\327 \203\207\330 A\204\207\331 (=\204\221\332\333\334 !!!\203\236\335 \210\324\336 \"\210\337 \202\270\340\341\342%\"!\203\265\335 \210\324\336 \"\210\337 \202\270\324\343!*)\207" [vc-mode buffer-file-name backend vc-make-backup-files backup-inhibited buffer-file-truename nil vc-file-clearprops add-hook vc-mode-line-hook vc-mode-line t err (vc-backend buffer-file-name) (((debug error) (message "Error: %S" err) nil)) make-local-variable vc-call-backend find-file-hook expand-file-name vc-backend message "Warning: symbolic link to %s-controlled source file" ask daemonp frame-list selected-frame get-file-buffer abbreviate-file-name file-chase-links vc-follow-link "Followed link to %s" vc-find-file-hook yes-or-no-p format "Symbolic link to %s-controlled source file; follow link? " "Warning: editing through the link bypasses version control" truename link-type vc-follow-symlinks noninteractive terminal-frame] 6 2577833])
apply(ad-Advice-vc-find-file-hook #[nil "\203\306 \205\272\307 !\210\310\311\312\306\313$\210\306\314\315\316\217\211\2036\312 \n\"\210 \204/\317\304!\210\313\320\n\321\"\202\271
\205=\322
!\211 $\205O $\232?\205O\323$!\211 %\204Y\306\202\270&\306=\203h\324\325%\"\202\270&\326=\203\221'\204\221\327 \203\207\330 A\204\207\331 (=\204\221\332\333\334 !!!\203\236\335 \210\324\336 \"\210\337 \202\270\340\341\342%\"!\203\265\335 \210\324\336 \"\210\337 \202\270\324\343!*)\207" [vc-mode buffer-file-name backend vc-make-backup-files backup-inhibited buffer-file-truename nil vc-file-clearprops add-hook vc-mode-line-hook vc-mode-line t err (vc-backend buffer-file-name) (((debug error) (message "Error: %S" err) nil)) make-local-variable vc-call-backend find-file-hook expand-file-name vc-backend message "Warning: symbolic link to %s-controlled source file" ask daemonp frame-list selected-frame get-file-buffer abbreviate-file-name file-chase-links vc-follow-link "Followed link to %s" vc-find-file-hook yes-or-no-p format "Symbolic link to %s-controlled source file; follow link? " "Warning: editing through the link bypasses version control" truename link-type vc-follow-symlinks noninteractive terminal-frame] 6 2577833] nil)
vc-find-file-hook()
run-hooks(find-file-hook)
after-find-file(nil t)
find-file-noselect-1(#<buffer foo<foo>> "/scp:k1:/home/atanu/foo/foo" nil nil "/scp:k1:/usr/home/atanu/foo/foo" ((265 . 48652) (-1 . 1)))
find-file-noselect("/scp:k1:/home/atanu/foo/foo" nil nil nil)
find-file("/scp:k1:/home/atanu/foo/foo")
dired-find-file()
call-interactively(dired-find-file nil nil)
command-execute(dired-find-file)