[SR-13475] swift-tools-version comment whitespace handling should be more helpful

[woolsweater]

Previous ID	SR-13475
Radar	rdar://problem/68115907
Original Reporter	@woolsweater
Type	Bug
Status	Closed
Resolution	Done

Environment

Swift Package Manager - Swift 5.3.0

Additional Detail from JIRA

Votes	0
Component/s
Labels	Bug
Assignee	@WowbaggersLiquidLunch
Priority	Medium

md5: fce3f911aee423772a66b24f8aa07b88

Issue Description:

The fix for SR-4134 introduced an error for unrecognized forms of the Package.swift swift-tools-version comment, but the error is generic and unhelpful when the only "misspelling" is whitespace:

/Users/me/some-project: error: the tools version '//swift-tools-version: 5.3' is not valid; consider using '// swift-tools-version:5.3' to specify the current tools version

Or:

/Users/me/some-project: error: the tools version '//swift-tools-version:5.3' is not valid; consider using '// swift-tools-version:5.3' to specify the current tools version

Really the problem here is that the parsing is overly strict with regards to whitespace. Requiring exactly a single space after the slashes and also none after the colon is unnecessarily arcane. The package manager should be able to work with any amount of space between the "tokens" of the comment, something like:

^//\s*swift-tools-version:\s*\d+\.\d+$

[typesanitizer]

@swift-ci create

[woolsweater]

This was resolved by the final version of swiftlang/swift-package-manager#2937

Thank you, @WowbaggersLiquidLunch!