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Running 'node' on Windows can show unhelpful error #577
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Thinking more, this may be a combination of the passthrough command and the fact that on Windows we currently always use
cmd.exe /C <command>when executing a Command. For passthrough cases, it may be better to create a direct command.Further investigation reveals the above solution won't work. Apparently by default, Windows uses the
PATHfrom the parent process (in this case the Volta shim) to look up an executable when usingstd::process::Command(see rust-lang/rust#15149). In order to combat that, if you set aPATHenvironment variable, Rust internally does a lookup to try to find the executable on the newPATH, and if it does find it then it uses it directly (see https://github.com/rust-lang/rust/blob/master/src/libstd/sys/windows/process.rs#L133-L149).However, in the case of passing through to a
nodethat doesn't exist, Rust looks fornodeand doesn't find it, so defaults to Windows' normal behavior, which uses the Volta shim's PATH to findnode, meaning it finds the shim itself again, and again, and again, until the OS breaks the chain of nested calls. When we usecmd.exe /C <command>, we get an extra layer that makes the PATHs work out, but we run into the error message issues.To properly support passthrough with correct PATH semantics and good error messages, we may need to create our own windows Command wrapper that provides a similar layer as calling
cmd.exe, but also provides a method for informing the top-level Volta process of it's inability to locate a command.Reacted by Rhys Lloyd
If you don't have a default Node selected and have no Node available elsewhere on the system, running
nodeon Windows results in the error message:'node' is not recognized as an internal or external command, operable program or batch fileI believe this is the result of the passthrough calling
nodewith the non-Volta path. On Unix, calling a non-existent command results in the call toCommand::statusreturning anErr. On Windows, it results in anOkwith a status code of 1. If possible, we should detect this situation and show the Volta error.One possibility would be to use
whichto see if there is something on the system path namednodeand only pass through if that succeeds.