+@option{-x} option can be used to enable tracing (@code{set -x}) of the
+currently run shell script @file{.do} file. @option{-xx} option enables
+tracing for all invoked @file{.do} files further.
+
+With @option{-j} option you can enable parallel builds, probably with an
+infinite number of workers (@code{=0}). Also you can set
+@env{$REDO_JOBS} to automatically apply that setting globally.
+
+With @option{-logs} (@env{$REDO_LOGS=1}) option you can capture job's
+@code{stderr} on the disk and read it later with @command{redo-log}
+command. Log's lines have @url{http://cr.yp.to/libtai/tai64.html,
+TAI64N} timestamp. You can decode it with @command{tai64nlocal} utility
+from @url{http://cr.yp.to/daemontools.html, daemontools}, or similar
+one: @code{go get go.cypherpunks.ru/tai64n/cmd/tai64nlocal}.
+@option{-silent} (@env{$REDO_SILENT=1}) omits @code{stderr} printing at
+all, but you can still capture it with @option{-logs}.
+
+@option{-log-pid} (@env{$REDO_LOG_PID=1}) can be used to prefix job's
+@code{stderr} with the PID, that could be useful during parallel builds.
+@option{-d} (@env{$REDO_DEBUG=1}) enables debug messages.
+
+@option{-no-progress} (@env{$REDO_NO_PROGRESS=1}) and
+@option{-no-status} (@env{$REDO_NO_STATUS=1}) disable statusline and
+progress display. @env{$NO_COLOR=1} disables progress/debug messages
+colouring.