I wanted to like Powershell, but it is missing some features that I think are essential. For example, apparently checking the return status of an arbitrary command is not trivial, and there's no equivalent of `-eu -o pipefail`. Yes, I know `-eu -o pipefail` is imperfect too, but it covers most common cases. I also struggled badly to stop it from mangling the output encoding of my applications (no, I don't want a goddamn BOM, thank you), and the solutions I found all either had no effect or required me to write what looked like C# code embedded in my shell script.
The upcoming 7.3 release had PSNativeCommandErrorActionPreference which was an experimental feature to implement pipefail https://learn.microsoft.com/en-us/powershell/scripting/learn.... It is no longer experimental and will be part of the actual release. This allows you to set `$PSNativeCommandUseErrorActionPreference = $true` rather than rely on `$ErrorActionPreference = 'Stop'` which does more than just treat non-zero rcs as a failure which is nice.
Otherwise for older versions you can just do `my.exe; if ($lastexitcode) { "failure code here" }`. It's not nice but certainly not impossible to do.
nounset is Set-StrictMode, errexit/pipefail is $ErrorActionPreference = 'stop' with $PSNativeCommandUseErrorActionPreference = $true. With those you can try/catch, which is infinitely better than the $?-based approach, but you can also use $? without them. PSCore encoding is always UTF-8 without BOM; you can enforce that the script is running on Core with #Requires -Version 6, or pass ($content | Out-String) to New-Item's -Value parameter for a v5-compatible hack.
