cc @ddunbar. I stuck this under Package Manager because the multitool support is all in service of swiftpm right now.

Sounds good.

I tried to figure out where this occurs, but could not. driver.cpp?

I don't know if this has been specifically fixed since the issue was filed or if something else has changed to make the problem go away, but I am not able to reproduce this in the most recent Swift builds. I can type `Swift build`, or `swift Build` and it all seems to work. If I mistype the subcommand, I get:

error: unable to invoke subcommand: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/swift-swift (No such file or directory)

but this seems expected.

Lee, do you remember the exact way in which you mistyped "swift"? From the original error message, I'm guessing you accidentally capitalized the leading "S"? Would you mind checking whether this is still a problem? As mentioned above, I tried a variety of ways to reproduce it but could not.

@swift-ci create