Duplicate command in 'commands' map

Using Swift
1

i just tried building this project, which was building just fine in january, and now Swift is giving me this error:

$ make
swift build -c debug -Xswiftc "-D" -Xswiftc "DEBUG" -Xcc -I/usr/local/include -Xlinker -L/usr/local/lib
Updating https://github.com/kelvin13/swift-opengl
Updating https://github.com/kelvin13/swiftxml
Fetching https://github.com/kelvin13/maxpng
Completed resolution in 1.63s
Cloning https://github.com/kelvin13/maxpng
Resolving https://github.com/kelvin13/maxpng at master
.build/debug.yaml:86:3: error: duplicate command in 'commands' map
  "<C.tests.exe>":
  ^~~~~~~~~~~~~~~
.build/debug.yaml:201:3: error: duplicate command in 'commands' map
  "C.tests.exe":
  ^~~~~~~~~~~~~
error: terminated(1): ~/tools/swift/usr/bin/swift-build-tool -f .build/debug.yaml main output:
    

Makefile:14: recipe for target 'debug' failed
make: *** [debug] Error 1

I was able to reduce the problem down to 3 modules (you can delete everything in that repo except sources/GLFW and Package.swift and of course Makefile)

let package = Package(
    name: "cloudgen",
    products: [],
    dependencies:
    [
        .package(url: "https://github.com/kelvin13/swift-opengl", .branch("master")),
        .package(url: "https://github.com/kelvin13/maxpng", .branch("master"))
    ],
    targets:
    [
        .target(name: "GLFW", path: "sources/GLFW")
    ]
)

but strangely, removing any of the three makes the other two compile fine. also, all the git urls are consistent normal urls, without the .git extension. What is going on?

2

Github doesn't require .git extensions; I assume it can distinguish between clone request vs a normal request, and serves the appropriate format.

3

This looks like a SwiftPM bug, do you mind filing a JIRA?