Debug launch freezes first time if envfile contents are long

[jahan01]

Environment data

• VS Code version: 1.29.1
• Extension version (available under the Extensions sidebar): 2018.11.0
• OS and version: OSX 10.14.1
• Python version (& distribution if applicable, e.g. Anaconda): 3.6
• Type of virtual environment used (N/A | venv | virtualenv | conda | ...): conda

Expected behaviour

Debugger should launch the program and start debugging

Actual behaviour

Launch sends only half contents to terminal and freezes. If you do a control C and relaunch debugger it runs smoothly. The issue happens only if the integrated terminal is created for the first time. When it reuses the exiting terminal, there is no issue.

Steps to reproduce:

1. Have a some what long content in envfile. Something like below
   .env

testenv1=testvar_testvar_testvar_testvar_testvar_testvar_testvar_testvar1
testenv2=testvar_testvar_testvar_testvar_testvar_testvar_testvar_testvar2
testenv3=testvar_testvar_testvar_testvar_testvar_testvar_testvar_testvar3
testenv4=testvar_testvar_testvar_testvar_testvar_testvar_testvar_testvar4
testenv5=testvar_testvar_testvar_testvar_testvar_testvar_testvar_testvar5
testenv6=testvar_testvar_testvar_testvar_testvar_testvar_testvar_testvar6
testenv7=testvar_testvar_testvar_testvar_testvar_testvar_testvar_testvar7
testenv8=testvar_testvar_testvar_testvar_testvar_testvar_testvar_testvar8
testenv9=testvar_testvar_testvar_testvar_testvar_testvar_testvar_testvar9

2. Set this file as envFile in your launch.json and start debugging.
3. First time it hangs. Only half the contents are transferred to terminal.
4. Do a ctrl + C and relaunch the debugging, it runs smoothly.

[DonJayamanne]

Please could you try this with the latest version of VS Code 1.30
I'm unable to replicate this at my end.

[jahan01]

I tried with latest 1.30 and I confirm this issue exists in the newer version as well. Please try to launch the debug in new terminal window and also I working in a conda virtual env.

You can also try reproducing with more env variables, add below lines to env files and it certainly fails at 1st launch in the session.

testenv10=testvar_testvar_testvar_testvar_testvar_testvar_testvar_testvar10
testenv11=testvar_testvar_testvar_testvar_testvar_testvar_testvar_testvar11
testenv12=testvar_testvar_testvar_testvar_testvar_testvar_testvar_testvar12
testenv13=testvar_testvar_testvar_testvar_testvar_testvar_testvar_testvar13
testenv14=testvar_testvar_testvar_testvar_testvar_testvar_testvar_testvar14

[jahan01]

@DonJayamanne please have a look and remove info needed label, if information is sufficient

[DonJayamanne]

Unfortunately I'm still unable to replicate this.

the debug in new terminal window and also I working in a conda virtual env.

Can you try using a non-conda environment.

[jahan01]

@DonJayamanne: I tried with os default python and the issue is reproducible. Btw, I am on Mac, if that helps. I tried with default terminal app and iterm2, also on bash/zsh shells, I am able reproduce in every combination. I am able to reproduce this in my colleague's system too.

[DonJayamanne]

I too tried this on a Mac.
As a temporary workaround, you can change the terminal to 'none' in your launch.json.

[jahan01]

@DonJayamanne: May be you could put more characters (double/triple) than your current in the env file

[DonJayamanne]

Still unable to replicate. Tried with 1,000,000 characters, and 20 variables.
Unfortunately I'm going to have to close this, as I'm unable to replicate this at my end.