Getting update-checkout failed, fix errors and try again

I'm just new and I can't figure out this error whenever I run utils/update-checkout --clone-with-ssh

Error:
======UPDATE FAILURES====== /Users/mohannedkandil/Desktop/swift-project/swift failed (ret=1): ['git', 'checkout', 'main'] b'error: The following untracked working tree files would be overwritten by checkout:\n\tBrewfile\n\tCHANGELOG.md\n\tCMakeLists.txt\n\tCODE_OF_CONDUCT.md\n\tCODE_OWNERS.TXT\n\tCONTRIBUTING.md\n\tLICENSE.txt\n\tREADME.md\n\tSwiftCompilerSources/.gitignore\n\tSwiftCompilerSources/CMakeLists.txt\n\tSwiftCompilerSources/Package.swift\n\tSwiftCompilerSources/README.md\n\tSwiftCompilerSources/Sources/AST/CMakeLists.txt\n\tSwiftCompilerSources/Sources/AST/DiagnosticEngine.swift\n\tSwiftCompilerSources/Sources/Basic/CMakeLists.txt\n\tSwiftCompilerSources/Sources/Basic/SourceLoc.swift\n\tSwiftCompilerSources/Sources/Basic/Utils.swift\n\tSwiftCompilerSources/Sources/CMakeLists.txt\n\tSwiftCompilerSources/Sources/Optimizer/Analysis/AliasAnalysis.swift\n\tSwiftCompilerSources/Sources/Optimizer/Analysis/CMakeLists.txt\n\tSwiftCompilerSources/Sources/Optimizer/Analysis/CalleeAnalysis.swift\n\tSwiftCompilerSources/Sources/Optimizer/Analysis/DeadEndBlocksAnalysis.swift\n\tSwiftCompilerSources/Sources/Optimizer/Analysis/DominatorTree.swift\n\tSwiftCompilerSources/Sources/Optimizer/Analysis/PostDominatorTree.swift\n\tSwiftCompilerSources/Sources/Optimizer/CMakeLists.txt\n\tSwiftCompilerSources/Sources/Optimizer/DataStructures/BasicBlockRange.swift\n\tSwiftCompilerSources/Sources/Optimizer/DataStructures/CMakeLists.txt\n\tSwiftCompilerSources/Sources/Optimizer/DataStructures/DeadEndBlocks.swift\n\tSwiftCompilerSources/Sources/Optimizer/DataStructures/FunctionUses.swift\n\tSwiftCompilerSources/Sources/Optimizer/DataStructures/InstructionRange.swift\n\tSwiftCompilerSources/Sources/Optimizer/DataStructures/ReachableBlocks.swift\n\tSwiftCompilerSources/Sources/Optimizer/DataStructures/Set.swift\n\tSwiftCompilerSources/Sources/Optimizer/DataStructures/Stack.swift\n\tSwiftCompilerSources/Sources/Optimizer/DataStructures/Worklist.swift\n\tSwiftCompilerSources/Sources/Optimizer/FunctionPasses/AssumeSingleThreaded.swift\n\tSwiftCompilerSources/Sources/Optimizer/FunctionPasses/CMakeLists.txt\n\tSwiftCompilerSources/Sources/Optimizer/FunctionPasses/CleanupDebugSteps.swift\n\tSwiftCompilerSources/Sources/Optimizer/FunctionPasses/ComputeEscapeEffects.swift\n\tSwiftCompilerSources/Sources/Optimizer/FunctionPasses/ComputeSideEffects.swift\n\tSwiftCompilerSources/Sources/Optimizer/FunctionPasses/DeadStoreElimination.swift\n\tSwiftCompilerSources/Sources/Optimizer/FunctionPasses/InitializeStaticGlobals.swift\n\tSwiftCompilerSources/Sources/Optimizer/FunctionPasses/MergeCondFails.swift\n\tSwiftCompilerSources/Sources/Optimizer/FunctionPasses/NamedReturnValueOptimization.swift\n\tSwiftCompilerSources/Sources/Optimizer/FunctionPasses/ObjCBridgingOptimization.swift\n\tSwiftCompilerSources/Sources/Optimizer/FunctionPasses/ObjectOutliner.swift\n\tSwiftCompilerSources/Sources/Optimizer/FunctionPasses/ReleaseDevirtualizer.swift\n\tSwiftCompilerSources/Sources/Optimizer/FunctionPasses/SimplificationPasses.swift\n\tSwiftCompilerSources/Sources/Optimizer/FunctionPasses/StackPromotion.swift\n\tSwiftCompilerSources/Sources/Optimizer/FunctionPasses/StripObjectHeaders.swift\n\tSwiftCompilerSources/Sources/Optimizer/InstructionSimplification/CMakeLists.txt\n\tSwiftCompilerSources/Sources/Optimizer/InstructionSimplification/SimplifyApply.swift\n\tSwiftCompilerSources/Sources/Optimizer/InstructionSimplification/SimplifyBeginCOWMutation.swift\n\tSwiftCompilerSources/Sources/Optimizer/InstructionSimplification/SimplifyBranch.swift\n\tSwiftCompilerSources/Sources/Optimizer/InstructionSimplification/SimplifyBuiltin.swift\n\tSwiftCompilerSources/Sources/Optimizer/InstructionSimplification/SimplifyCondBranch.swift\n\tSwiftCompilerSources/Sources/Optimizer/InstructionSimplification/SimplifyCondFail.swift\n\tSwiftCompilerSources/Sources/Optimizer/InstructionSimplification/SimplifyDebugStep.swift\n\tSwiftCompilerSources/Sources/Optimizer/InstructionSimplification/SimplifyDestructure.swift\n\tSwiftCompilerSources/Sources/Optimizer/InstructionSimplification/SimplifyGlobalValue.swift\n\tSwiftCompilerSources/Sources/Optimizer/InstructionSimplification/SimplifyInitEnumDataAddr.swift\n\tSwiftCompilerSources/Sources/Optimizer/InstructionSimplification/SimplifyLoad.swift\n\tSwiftCompilerSources/Sources/Optimizer/\nAborting\n' update-checkout failed, fix errors and try again

This means you need to either check in or move these files out of your swift-project/swift directory and re-run the script since otherwise git checkout fails

do u mean to remove the build files ?

It looks like something is dirty in the swift git repo, you can cd into that repo and run git status, that should ideally be empty when pulling. You can also just git pull in that directory and resolve issues there.