spawnSync should allow options.shell:Bool and Sys.command should use it

[back2dos]

Try Sys.command("start", "http://example.com") on Windows. Works on neko, but not with hxnodejs, because it needs to be run through the shell. Interestingly the externs don't mention that option, but if you force your will it works as expected.

[mikicho]

@kevinresol / @back2dos , please close the issue if fixed

[kevinresol]

Reading the PR again, I think Sys.command("start http://example.com") will work