Better "file not found" error message

[thePianoKid]

If you reference a file that doesn't exist in Package.swift, you get this error:

*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[NSNull length]: unrecognized selector sent to instance 0x1fc8bf700'
*** First throw call stack:
(
        0   CoreFoundation                      0x000000018f54abf0 __exceptionPreprocess + 176
        1   libobjc.A.dylib                     0x000000018efd691c objc_exception_throw + 88
        2   CoreFoundation                      0x000000018f60bc6c -[NSObject(NSObject) __retain_OA] + 0
        3   CoreFoundation                      0x000000018f4bbbc8 ___forwarding___ + 1480
        4   CoreFoundation                      0x000000018f4bb540 _CF_forwarding_prep_0 + 96
        5   Foundation                          0x00000001910f00a0 $ss5ErrorP10FoundationE20localizedDescriptionSSvg + 980
        6   swift-package                       0x000000010642cb8c $s9WorkspaceAAC22BinaryArtifactsManagerV7extract_18artifactsDirectory18observabilityScopeSayAB15ManagedArtifactVGAJ_6Basics12AbsolutePathVAK013ObservabilityI0CtYaKFAJScgyAISgs5Error_pGzYaKXEfU_AP  7   swift-package                       0x000000010643ed6d $s9WorkspaceAAC22BinaryArtifactsManagerV7extract_18artifactsDirectory18observabilityScopeSayAB15ManagedArtifactVGAJ_6Basics12AbsolutePathVAK013ObservabilityI0CtYaKFAJScgyAISgs5Error_pGzYaKXEfU_AP 8   libswift_Concurrency.dylib          0x0000000293b2aec5 _ZL23completeTaskWithClosurePN5swift12AsyncContextEPNS_10SwiftErrorE + 1
)
libc++abi: terminating due to uncaught exception of type NSException

💣 Program crashed: Signal 6: Backtracing from 0x18f3e45e8...

This PR throws this error instead:

error: local archive of binary target 'bin.zip' at '~/Desktop/Code/sandbox/ReproRdar177455391/bin.zip' does not exist.

[bkhouri]

Since we didn't start the testing against this change, can we target the PR to release/6.4.x and then let the automerger bring it to main?

[bkhouri]

suggestion: consider changing targetName to target to ensure the caller sends an "expected" value.

Suggested change

	static func localArchiveNotFound(archivePath: AbsolutePath, targetName: String) -> Self {
	.init(description: "local archive of binary target '\(targetName)' at '\(archivePath)' does not exist.")
	}
	static func localArchiveNotFound(archivePath: AbsolutePath, target: Target) -> Self {
	.init(description: "local archive of binary target '\(target.name)' at '\(archivePath)' does not exist.")
	}

[thePianoKid]

I think we should refactor every error so it references a target object instead of a string. This is outside the scope of this PR, so I made this one.

[thePianoKid]

@swift-ci test

[bkhouri]

@swift-ci test

[bripeticca]

@swift-ci test

[thePianoKid]

@swift-ci test

[bkhouri]

@swift-ci test self hosted windows

[bkhouri]

@swift-ci test macOS

[bkhouri]

@swift-ci test linux

[thePianoKid]

@swift-ci test linux

[thePianoKid]

@swift-ci test macOS

[thePianoKid]

hmmm... I found a simpler solution.

I changed the definition of FileSystemError in TSC to fall back to self:

extension FileSystemError: CustomNSError {
    public var errorUserInfo: [String : Any] {
        return [NSLocalizedDescriptionKey: localizedMessage ?? "\(self)"]
    }
}

When the target doesn't exist, an error is thrown with no localizedMessage. Trying to unwrap nil was what was crashing SPM. FileSystemError already has handling for when there is no localizedMessage . It's in Diagnostics.swift.

swiftlang/swift-tools-support-core#563 adds the ?? \(self) to TSC.

I'm closing this PR because swiftlang/swift-tools-support-core#563 already fixes this issue.