tramp messages are raised with verbosity levels ranging from 0
to 10. tramp does not display all messages; only those with a
verbosity level less than or equal to
The verbosity levels are
0 silent (no tramp messages at all)
3 connection to remote hosts (default verbosity)
6 sent and received strings
7 file caching
8 connection properties
9 test commands
10 traces (huge)
tramp-verbose greater than or equal to 4, messages are
also written to a tramp debug buffer. Such debug buffers are
essential to bug and problem analyses. For tramp bug reports,
tramp-verbose level to 6 (see Bug Reports).
The debug buffer is in Outline Mode. In this buffer, messages can be filtered by their level. To see messages up to verbosity level 5, enter C-u 6 C-c C-q.
tramp handles errors internally. But to get a Lisp backtrace, both the error and the signal have to be set as follows:
(setq debug-on-error t debug-on-signal t)
To enable stepping through tramp function call traces, they have to be specifically enabled as shown in this code:
(require 'trace) (dolist (elt (all-completions "tramp-" obarray 'functionp)) (trace-function-background (intern elt))) (untrace-function 'tramp-read-passwd) (untrace-function 'tramp-gw-basic-authentication)
The buffer *trace-output* contains the output from the function
call traces. Disable
tramp-gw-basic-authentication to stop password strings from
being written to *trace-output*.