Someone enabled wd/plot debug logging in the beta?
$ ./jqt &
$ j first line "(3 : '0!:0 y')<BINPATH,'/profile.ijs'[ARGV_z_=:,<'./jqt'[UNAME_z_=:'Linux'[BINPATH_z_=:'/home/me/software/j9.6/bin'[LIBFILE_z_=:'/home/me/software/j9.6/bin/libj.so'[FHS_z_=:0[IFQT_z_=:1[libjqt_z_=:'/home/me/software/j9.6/bin/libjqt.so'"
7
wd a1 0version7
wd a1 0version6
wd a1 0qosver3
NB. And then use jqt to do a plot; say, plot (];%) i:10
wd a1 0qpx15
wd a1 0pc plot closeok6
wd a1 0qhwndp16
wd a1 0menupop "&File";33
wd a1 0menu quit "&Quit" "Ctrl+Q" "" "";9
wd a1 0menupopz;8
wd a1 0pn *Plot13
wd a1 0minwh 480 36020
wd a1 0cc gs isigraph flush7
wd a1 0pas 0 06
wd a1 0pshow 6
wd a1 0ptop 01
wd a1 0q1
wd a1 0q4
wd a1 0msgs1
wd a1 0q4
wd a1 0msgs1
... keep printing as long as you interact with the plot window ...