solver: ValidateParams skip alt src PR validation

This change modifies the ValidateParams() function ignore deducing
project root of projects that have an alternate source. This is needed
when the project repository is not reachable and an alternate repo is
used.

Author: darkowlzz

gps/solver.go

@@ -399,6 +399,17 @@ func (e DeductionErrs) Error() string {
 
 // ValidateParams validates the solver parameters to ensure solving can be completed.
 func ValidateParams(params SolveParameters, sm SourceManager) error {
+	// Create a list of projects to skip project root deduction. This is
+	// required for projects with an alternate source.
+	altSrc := make(map[string]bool)
+	if params.Manifest != nil {
+		for proj, prop := range params.Manifest.DependencyConstraints() {
+			if prop.Source != "" {
+				altSrc[string(proj)] = true
+			}
+		}
+	}
+
 	// Ensure that all packages are deducible without issues.
 	var deducePkgsGroup sync.WaitGroup
 	deductionErrs := make(DeductionErrs)
@@ -420,6 +431,10 @@ func ValidateParams(params SolveParameters, sm SourceManager) error {
 	}
 
 	for _, ip := range rd.externalImportList(paths.IsStandardImportPath) {
+		if altSrc[ip] {
+			// Skip project root deduction for project with alternate source.
+			continue
+		}
 		deducePkgsGroup.Add(1)
 		go deducePkg(ip, sm)
 	}