Code Coverage Diff not generated

[Shashikant86]

While generating the diff of the code coverage report, followed the documentation from man xccov and Xcode 10.2 release notes

Env

Xcode Version: Version 10.2 (10E125)
Swift Version:

Apple Swift version 5.0 (swiftlang-1001.0.69.5 clang-1001.0.46.3)
Target: x86_64-apple-darwin18.5.0

Steps to Reproduce

Created this project for a demo of xccov, you can clone and try to create diff.
View reports and merge report works perfect. However, coverage diff doesn't work as expected

Details in the post here

$ git clone 
$ cd XCCov-Demo
 $ xcodebuild -project XCCov-Demo.xcodeproj/ -scheme XCCov-Demo -derivedDataPath Build/ -destination 'platform=iOS Simulator,OS=12.2,name=iPhone Xʀ' -enableCodeCoverage YES clean build test CODE_SIGN_IDENTITY="" CODE_SIGNING_REQUIRED=NO

Create Diff by various CLI

• Attempt One

 
Error: Error Domain=XCCovErrorDomain Code=0 "Failed to load coverage report at path Build/Logs/Test/Run-XCCov-Demo-2019.04.03_07-40-58-+0100.xcresult/3_Test/action.xccovreport," UserInfo={NSLocalizedDescription=Failed to load coverage report at path Build/Logs/Test/Run-XCCov-Demo-2019.04.03_07-40-58-+0100.xcresult/3_Test/action.xccovreport,, NSUnderlyingError=0x7f93dec23600 {Error Domain=NSCocoaErrorDomain Code=260 "The file “action.xccovreport,” couldn’t be opened because there is no such file." UserInfo={NSFilePath=/Users/shashi/workspace/XCCov-Demo/Build/Logs/Test/Run-XCCov-Demo-2019.04.03_07-40-58-+0100.xcresult/3_Test/action.xccovreport,, NSUnderlyingError=0x7f93dec23110 {Error Domain=NSPOSIXErrorDomain Code=2 "No such file or directory"}}}}

• Attempt 2:

$ xcrun xccov diff --json --path-equivalence Build/Logs/Test/Run-XCCov-Demo-2019.04.03_07-40-58-+0100.xcresult/3_Test/action.xccovreport, Build/Logs/Test/Run-XCCov-Demo-2019.04.03_07-52-58-+0100.xcresult/3_Test/action.xccovreport

Error: Must supply the path to two coverage reports to diff

• Attempt Three

$xcrun xccov diff --json from --path-equivalence Build/Logs/Test/Run-XCCov-Demo-2019.04.03_07-33-02-+0100.xcresult/3_Test/action.xccovreport,to Build/Logs/Test/Run-XCCov-Demo-2019.04.03_07-52-58-+0100.xcresult/3_Test/action.xccovreport

Error: Error Domain=XCCovErrorDomain Code=0 "Failed to load coverage report at path from" UserInfo={NSLocalizedDescription=Failed to load coverage report at path from, NSUnderlyingError=0x7fc2da631430 {Error Domain=NSCocoaErrorDomain Code=260 "The file “from” couldn’t be opened because there is no such file." UserInfo={NSFilePath=/Users/shashi/workspace/XCCov-Demo/from, NSUnderlyingError=0x7fc2da606680 {Error Domain=NSPOSIXErrorDomain Code=2 "No such file or directory"}}}}

• Attempt Four

xcrun xccov diff --json --path-equivalence from Build/Logs/Test/Run-XCCov-Demo-2019.04.03_07-33-02-+0100.xcresult/3_Test/action.xccovreport,to Build/Logs/Test/Run-XCCov-Demo-2019.04.03_07-52-58-+0100.xcresult/3_Test/action.xccovreport

fish: 'xcrun xccov diff --json --path-…' terminated by signal SIGSEGV (Address boundary error)

Just wondering what's right command to generate Code Coverage Diff?