Thanks for trying to help me with this Starting-the-Terminal problem.
I work at two different PCs with nearly identical setup. Both rstudios had this problem, but only on one of them it goes away after a while. I don't know why, because I've observed this behaviour only twice, and realized it only much later after the error went away.
Maybe it has to do with doing a "Restart R Session" and repeatedly restarting an in- IDE webserver while working with the blogdown package. This package creates a preview of a blog post inside the RStudio IDE.
I didn't install blogdown on my work PC yet, where I wasn't able to get a terminal inside Rstudio.
Now here is the full output of Terminal Diagnostics when it's working properly:
Global Terminal Information
---------------------------
Loaded TerminalSessions: 1
Handle: '271D147C' Caption: 'Terminal 1'
Terminal List Count: 2
Handle: '271D147C' Caption: 'Terminal 1' Session Created: true
Handle: 'C1E78D68' Caption: 'Terminal 2' Session Created: false
Current Terminal Session Information
------------------------------------
Caption: 'Terminal 1'
Title: '/home/knut/code/git/_my/R_stuff/ggplot2-expermt'
Cols x Rows '107 x 13'
Shell: 'Bash'
Handle: '271D147C'
Sequence: '1'
Restarted: 'true
Busy: 'false'
Exit Code: 'null'
Full screen: 'client=false/server=false'
Zombie: 'false'
Track Env 'true'
Local-echo: 'true'
Working Dir: '~/code/git/_my/R_stuff/ggplot2-expermt'
Interactive: 'Always'
WebSockets: 'true'
Typing lag: '0ms'
System Information
------------------
Desktop: 'true'
Platform: 'Linux'
Connection Information
----------------------
2017/11/26 9:21:50: Connect WebSocket: 'ws://127.0.0.1:6788/terminal/271D147C/'
2017/11/26 9:21:50: WebSocket connected
Local-echo Match Failures
-------------------------
<none>
Try turning off all the following Terminal options, then opening a new terminal.
Local terminal echo
Connect with WebSockets
Save and restore environment variables
If that makes it work, then try to figure out which one(s) it was. The terminal is slower (typing lag) without websockets and local echo, so try turning them back on one at a time and opening a new terminal, etc.