Hyper: Powershell causes ArgumentNullException during Hyper startup

[cdmihai]

• [x] I am on the latest Hyper.app version
• [x] I have searched the issues of this repo and believe that this is not a duplicate

• OS version and name: Windows 10 1809
• Hyper.app version: 3.0.0 Canary 8 and 2.1.2
• Link of a Gist with the contents of your .hyper.js: https://gist.github.com/cdmihai/aca48f61697004281661ee11a7aee04e
  

  Issue

By unzipping powershell 6.1.3 (no machine install) and pointing Hyper to its executable, I get the following:

Hyper 2.1.2 has better formatting:

[ppot]

Seem like a Cmdlet problem. What are you trying to do? I could test this at my PC with hyper on it.

[cdmihai]

I am trying to use the latest powershell release with Hyper. I unzip powershell, point .hyper.js to its exe, start up hyper, and I get that on startup. It's either a Hyper - Powershell compatibility problem (like powershell breaking back compat), or there's some random machine specific issue that's breaking my Hyper startup on powershell 6.1.3, but not on the machine installed powershell.

[ppot]

I can't use psh with the lastest version...

[cdmihai]

I can't use psh with the lastest version...

What is psh (perl shell, powershell) and whose latest version are you referring to (powershell, hyper)? But yes, that's also my impression, latest Hyper does not work with latest Powershell.

[ppot]

powershell. I'm on 5 and won't upgrade at work on 6.x for development reason.

[Stanzilla]

[cdmihai]

Looks like it's something specific to my machine. I tried it with all combinations, x86 / x64, zip / msi, and I get the same thing. I'll post the fix here when I get some time to debug it.

[Astrophizz]

There's some difference between running pwsh at launch or after. If pwsh.exe is specified as the shell to run when spawning a new session, hyper crashes with this exception. However, launching pwsh.exe from the default CMD shell works fine.

[cdmihai]

@Stanzilla, I suggest you reopen the issue. I am launching powershell via the hyper.js script (link to contents in the description) when getting this error.

[Stanzilla]

@cdmihai Just tried again and it still works, both

shell: 'C:\\Program Files\\PowerShell\\6\\pwsh.exe',

with a system install and

shell: 'E:\\tools\\Powershell\\pwsh.exe', with the zip extracted version

[Astrophizz]

I found how to make hyper spawn with pwsh.exe and not crash: shellArgs needs to be empty (an empty array). Interestingly the same solution is in another issue for a different error: https://github.com/zeit/hyper/issues/3269#issuecomment-433714051. In his scenario he was using the default shellArgs: ['--login']. In contrast, I was using shellArgs: [''] as suggested here https://github.com/zeit/hyper/issues/1020#issuecomment-272072997 and here https://github.com/zeit/hyper/issues/2438#issuecomment-342734721. The empty string solution no longer works - probably due to a change in how powershell handles arguments.

[Astrophizz]

Unless I'm misreading something, this https://github.com/PowerShell/PowerShell/commit/1523c218a6537ad367f42fcd8ad85711d7596770#diff-72f893ea967967a637206a8b9a6385cbR543 converts the empty string to null and guarantees an exception. That change was released with Powershell 6.1.0.

[cdmihai]

@Astrophizz, that seems to be the issue, empty string being converted to null which leads to the exception. Using something benign like shellArgs: ['-NoLogo'] avoids that and makes it work. Interesting why @Stanzilla didn't hit it. @Stanzilla, what value did you use for shellArgs?