Introduce install --relaxed

It introduces a relaxed way to install packages with loose deps. Default
installation now will by default prefer up-to-date packages during
selection.

Also:
- Upgrade now it's used in install so it have to return the full system view also when there is nothing to upgrade
- Avoid checking upgrade upfront if relaxed is on

cmd/install.go

@@ -104,6 +104,7 @@ To force install a package:
 			PreserveSystemEssentialData: true,
 			DownloadOnly:                downloadOnly,
 			Ask:                         !yes,
+			Relaxed:                     relax,
 		})
 		inst.Repositories(repos)
 
@@ -125,6 +126,8 @@ func init() {
 	installCmd.Flags().Float32("solver-discount", 1.0, "Solver discount rate")
 	installCmd.Flags().Int("solver-attempts", 9000, "Solver maximum attempts")
 	installCmd.Flags().Bool("nodeps", false, "Don't consider package dependencies (harmful!)")
+	installCmd.Flags().Bool("relax", false, "Relax installation constraints")
+
 	installCmd.Flags().Bool("onlydeps", false, "Consider **only** package dependencies")
 	installCmd.Flags().Bool("force", false, "Skip errors and keep going (potentially harmful)")
 	installCmd.Flags().Bool("solver-concurrent", false, "Use concurrent solver (experimental)")

pkg/installer/installer.go

@@ -50,6 +50,7 @@ type LuetInstallerOptions struct {
 	SolverUpgrade, RemoveUnavailableOnUpgrade, UpgradeNewRevisions bool
 	Ask                                                            bool
 	DownloadOnly                                                   bool
+	Relaxed                                                        bool
 }
 
 type LuetInstaller struct {
@@ -513,7 +514,7 @@ func (l *LuetInstaller) Install(cp pkg.Packages, s *System) error {
 		return err
 	}
 
-	if len(s.Database.World()) > 0 {
+	if len(s.Database.World()) > 0 && !l.Options.Relaxed {
 		Info(":thinking: Checking for available upgrades")
 		if err := l.checkAndUpgrade(syncedRepos, s); err != nil {
 			return errors.Wrap(err, "while checking upgrades before install")
@@ -684,7 +685,12 @@ func (l *LuetInstaller) computeInstall(o Option, syncedRepos Repositories, cp pk
 
 	if !o.NoDeps {
 		solv := solver.NewResolver(solver.Options{Type: l.Options.SolverOptions.Implementation, Concurrency: l.Options.Concurrency}, s.Database, allRepos, pkg.NewInMemoryDatabase(false), l.Options.SolverOptions.Resolver())
+
+		if l.Options.Relaxed {
+			solution, err = solv.RelaxedInstall(p)
+		} else {
 			solution, err = solv.Install(p)
+		}
 		/// TODO: PackageAssertions needs to be a map[fingerprint]pack so lookup is in O(1)
 		if err != nil && !o.Force {
 			return toInstall, p, solution, allRepos, errors.Wrap(err, "Failed solving solution for package")

pkg/package/package.go

@@ -72,6 +72,7 @@ type Package interface {
 	SetVersion(string)
 	RequiresContains(PackageDatabase, Package) (bool, error)
 	Matches(m Package) bool
+	AtomMatches(m Package) bool
 	BumpBuildVersion() error
 
 	AddUse(use string)
@@ -536,6 +537,13 @@ func (p *DefaultPackage) Matches(m Package) bool {
 	return false
 }
 
+func (p *DefaultPackage) AtomMatches(m Package) bool {
+	if p.GetName() == m.GetName() && p.GetCategory() == m.GetCategory() {
+		return true
+	}
+	return false
+}
+
 func (p *DefaultPackage) Mark() Package {
 	marked := p.Clone()
 	marked.SetName("@@" + marked.GetName())
@@ -795,37 +803,38 @@ func (pack *DefaultPackage) buildFormula(definitiondb PackageDatabase, db Packag
 				required = requiredDef
 			} else {
 
-				var ALO, priorityConstraints, priorityALO []bf.Formula
+				var ALO []bf.Formula // , priorityConstraints, priorityALO []bf.Formula
 
 				// Try to prio best match
 				// Force the solver to consider first our candidate (if does exists).
 				// Then builds ALO and AMO for the requires.
-				c, candidateErr := definitiondb.FindPackageCandidate(requiredDef)
-				var C bf.Formula
-				if candidateErr == nil {
-					// We have a desired candidate, try to look a solution with that included first
-					for _, o := range packages {
-						encodedB, err := o.Encode(db)
-						if err != nil {
-							return nil, err
-						}
-						B := bf.Var(encodedB)
-						if !o.Matches(c) {
-							priorityConstraints = append(priorityConstraints, bf.Not(B))
-							priorityALO = append(priorityALO, B)
-						}
-					}
-					encodedC, err := c.Encode(db)
-					if err != nil {
-						return nil, err
-					}
-					C = bf.Var(encodedC)
-					// Or the Candidate is true, or all the others might be not true
-					// This forces the CDCL sat implementation to look first at a solution with C=true
-					formulas = append(formulas, bf.Or(bf.Not(A), bf.Or(bf.And(C, bf.Or(priorityConstraints...)), bf.And(bf.Not(C), bf.Or(priorityALO...)))))
-				}
+				// c, candidateErr := definitiondb.FindPackageCandidate(requiredDef)
+				// var C bf.Formula
+				// if candidateErr == nil {
+				// 	// We have a desired candidate, try to look a solution with that included first
+				// 	for _, o := range packages {
+				// 		encodedB, err := o.Encode(db)
+				// 		if err != nil {
+				// 			return nil, err
+				// 		}
+				// 		B := bf.Var(encodedB)
+				// 		if !o.Matches(c) {
+				// 			priorityConstraints = append(priorityConstraints, bf.Not(B))
+				// 			priorityALO = append(priorityALO, B)
+				// 		}
+				// 	}
+				// 	encodedC, err := c.Encode(db)
+				// 	if err != nil {
+				// 		return nil, err
+				// 	}
+				// 	C = bf.Var(encodedC)
+				// 	// Or the Candidate is true, or all the others might be not true
+				// 	// This forces the CDCL sat implementation to look first at a solution with C=true
+				// 	//formulas = append(formulas, bf.Or(bf.Not(A), bf.Or(bf.And(C, bf.Or(priorityConstraints...)), bf.And(bf.Not(C), bf.Or(priorityALO...)))))
+				// 	formulas = append(formulas, bf.Or(C, bf.Or(priorityConstraints...)))
+				// }
 
-				// AMO - At most one
+				// AMO/ALO - At most/least one
 				for _, o := range packages {
 					encodedB, err := o.Encode(db)
 					if err != nil {

pkg/solver/decoder_test.go

@@ -415,6 +415,7 @@ var _ = Describe("Decoder", func() {
 
 				orderW, err := solution.Order(dbDefinitions, W.GetFingerPrint())
 				Expect(err).ToNot(HaveOccurred())
+				Expect(len(orderW) > 0).To(BeTrue())
 				Expect(orderW[0].Package.GetName()).To(Equal("X"))
 				Expect(orderW[1].Package.GetName()).To(Equal("Y"))
 				Expect(orderW[2].Package.GetName()).To(Equal("Z"))

pkg/solver/parallel.go

@@ -550,6 +550,13 @@ func (s *Parallel) UpgradeUniverse(dropremoved bool) (pkg.Packages, PackagesAsse
 // Upgrade compute upgrades of the package against the world definition.
 // It accepts two boolean indicating if it has to check for conflicts or try to attempt a full upgrade
 func (s *Parallel) Upgrade(checkconflicts, full bool) (pkg.Packages, PackagesAssertions, error) {
+	return s.upgrade(s.DefinitionDatabase, s.InstalledDatabase, checkconflicts, full)
+
+}
+
+// Upgrade compute upgrades of the package against the world definition.
+// It accepts two boolean indicating if it has to check for conflicts or try to attempt a full upgrade
+func (s *Parallel) upgrade(defDB pkg.PackageDatabase, installDB pkg.PackageDatabase, checkconflicts, full bool) (pkg.Packages, PackagesAssertions, error) {
 
 	// First get candidates that needs to be upgraded..
 
@@ -557,7 +564,7 @@ func (s *Parallel) Upgrade(checkconflicts, full bool) (pkg.Packages, PackagesAss
 	toInstall := pkg.Packages{}
 
 	// we do this in memory so we take into account of provides
-	universe, err := s.DefinitionDatabase.Copy()
+	universe, err := defDB.Copy()
 	if err != nil {
 		return nil, nil, errors.Wrap(err, "Could not copy def db")
 	}
@@ -595,7 +602,7 @@ func (s *Parallel) Upgrade(checkconflicts, full bool) (pkg.Packages, PackagesAss
 		}
 	}()
 
-	for _, p := range s.InstalledDatabase.World() {
+	for _, p := range installDB.World() {
 		all <- p
 	}
 
@@ -604,7 +611,7 @@ func (s *Parallel) Upgrade(checkconflicts, full bool) (pkg.Packages, PackagesAss
 	close(results)
 	wg2.Wait()
 
-	s2 := &Parallel{Concurrency: s.Concurrency, InstalledDatabase: installedcopy, DefinitionDatabase: s.DefinitionDatabase, ParallelDatabase: pkg.NewInMemoryDatabase(false)}
+	s2 := &Parallel{Concurrency: s.Concurrency, InstalledDatabase: installedcopy, DefinitionDatabase: defDB, ParallelDatabase: pkg.NewInMemoryDatabase(false)}
 	s2.SetResolver(s.Resolver)
 	if !full {
 		ass := PackagesAssertions{}
@@ -855,6 +862,32 @@ func (s *Parallel) Install(c pkg.Packages) (PackagesAssertions, error) {
 		}
 		return ass, nil
 	}
-
-	return s.Solve()
+	assertions, err := s.Solve()
+	if err != nil {
+		return nil, err
+	}
+
+	return s.upgradeAssertions(assertions)
+}
+
+func (s *Parallel) upgradeAssertions(assertions PackagesAssertions) (PackagesAssertions, error) {
+
+	systemAfterInstall := pkg.NewInMemoryDatabase(false)
+
+	for _, p := range assertions {
+		if p.Value {
+			systemAfterInstall.CreatePackage(p.Package)
+		}
+	}
+
+	_, assertions, err := s.upgrade(s.DefinitionDatabase, systemAfterInstall, false, false)
+	if err != nil {
+		return nil, err
+	}
+
+	// for _, u := range toUninstall {
+	// 	systemAfterInstall.RemovePackage()
+
+	// }
+	return assertions, nil
 }

pkg/solver/solver.go

@@ -37,6 +37,8 @@ const (
 type PackageSolver interface {
 	SetDefinitionDatabase(pkg.PackageDatabase)
 	Install(p pkg.Packages) (PackagesAssertions, error)
+	RelaxedInstall(p pkg.Packages) (PackagesAssertions, error)
+
 	Uninstall(checkconflicts, full bool, candidate ...pkg.Package) (pkg.Packages, error)
 	ConflictsWithInstalled(p pkg.Package) (bool, error)
 	ConflictsWith(p pkg.Package, ls pkg.Packages) (bool, error)
@@ -51,6 +53,7 @@ type PackageSolver interface {
 	SetResolver(PackageResolver)
 
 	Solve() (PackagesAssertions, error)
+	//	BestInstall(c pkg.Packages) (PackagesAssertions, error)
 }
 
 // Solver is the default solver for luet
@@ -493,34 +496,47 @@ func (s *Solver) UpgradeUniverse(dropremoved bool) (pkg.Packages, PackagesAssert
 	return markedForRemoval, assertion, nil
 }
 
-func (s *Solver) Upgrade(checkconflicts, full bool) (pkg.Packages, PackagesAssertions, error) {
-
-	// First get candidates that needs to be upgraded..
+func inPackage(list []pkg.Package, p pkg.Package) bool {
+	for _, l := range list {
+		if l.AtomMatches(p) {
+			return true
+		}
+	}
+	return false
+}
 
+// Compute upgrade between packages if specified, or all if none is specified
+func (s *Solver) computeUpgrade(pps ...pkg.Package) func(defDB pkg.PackageDatabase, installDB pkg.PackageDatabase) (pkg.Packages, pkg.Packages, pkg.PackageDatabase) {
+	return func(defDB pkg.PackageDatabase, installDB pkg.PackageDatabase) (pkg.Packages, pkg.Packages, pkg.PackageDatabase) {
 		toUninstall := pkg.Packages{}
 		toInstall := pkg.Packages{}
 
 		// we do this in memory so we take into account of provides, and its faster
-	universe, err := s.DefinitionDatabase.Copy()
-	if err != nil {
-		return nil, nil, errors.Wrap(err, "failed creating db copy")
-	}
+		universe, _ := defDB.Copy()
 
 		installedcopy := pkg.NewInMemoryDatabase(false)
 
-	for _, p := range s.InstalledDatabase.World() {
+		for _, p := range installDB.World() {
 			installedcopy.CreatePackage(p)
 			packages, err := universe.FindPackageVersions(p)
 			if err == nil && len(packages) != 0 {
 				best := packages.Best(nil)
-			if !best.Matches(p) {
+				if !best.Matches(p) && len(pps) == 0 ||
+					len(pps) != 0 && inPackage(pps, p) {
 					toUninstall = append(toUninstall, p)
 					toInstall = append(toInstall, best)
 				}
 			}
 		}
+		return toUninstall, toInstall, installedcopy
+	}
+}
 
-	s2 := NewSolver(Options{Type: SingleCoreSimple}, installedcopy, s.DefinitionDatabase, pkg.NewInMemoryDatabase(false))
+func (s *Solver) upgrade(fn func(defDB pkg.PackageDatabase, installDB pkg.PackageDatabase) (pkg.Packages, pkg.Packages, pkg.PackageDatabase), defDB pkg.PackageDatabase, installDB pkg.PackageDatabase, checkconflicts, full bool) (pkg.Packages, PackagesAssertions, error) {
+
+	toUninstall, toInstall, installedcopy := fn(defDB, installDB)
+
+	s2 := NewSolver(Options{Type: SingleCoreSimple}, installedcopy, defDB, pkg.NewInMemoryDatabase(false))
 	s2.SetResolver(s.Resolver)
 	if !full {
 		ass := PackagesAssertions{}
@@ -541,15 +557,20 @@ func (s *Solver) Upgrade(checkconflicts, full bool) (pkg.Packages, PackagesAsser
 	}
 
 	if len(toInstall) == 0 {
-		return toUninstall, PackagesAssertions{}, nil
+		ass := PackagesAssertions{}
+		for _, i := range installDB.World() {
+			ass = append(ass, PackageAssert{Package: i.(*pkg.DefaultPackage), Value: true})
+		}
+		return toUninstall, ass, nil
 	}
 
-	assertions, err := s2.Install(toInstall.Unique())
+	assertions, err := s2.RelaxedInstall(toInstall.Unique())
 
 	return toUninstall, assertions, err
-	// To that tree, ask to install the versions that should be upgraded, and try to solve
-	// Return the solution
+}
 
+func (s *Solver) Upgrade(checkconflicts, full bool) (pkg.Packages, PackagesAssertions, error) {
+	return s.upgrade(s.computeUpgrade(), s.DefinitionDatabase, s.InstalledDatabase, checkconflicts, full)
 }
 
 // Uninstall takes a candidate package and return a list of packages that would be removed
@@ -619,7 +640,7 @@ func (s *Solver) Uninstall(checkconflicts, full bool, packs ...pkg.Package) (pkg
 	s2.SetResolver(s.Resolver)
 
 	// Get the requirements to install the candidate
-	asserts, err := s2.Install(toRemove)
+	asserts, err := s2.RelaxedInstall(toRemove)
 	if err != nil {
 		return nil, err
 	}
@@ -729,7 +750,7 @@ func (s *Solver) Solve() (PackagesAssertions, error) {
 
 // Install given a list of packages, returns package assertions to indicate the packages that must be installed in the system in order
 // to statisfy all the constraints
-func (s *Solver) Install(c pkg.Packages) (PackagesAssertions, error) {
+func (s *Solver) RelaxedInstall(c pkg.Packages) (PackagesAssertions, error) {
 
 	coll, err := s.getList(s.DefinitionDatabase, c)
 	if err != nil {
@@ -749,6 +770,59 @@ func (s *Solver) Install(c pkg.Packages) (PackagesAssertions, error) {
 		}
 		return ass, nil
 	}
-
-	return s.Solve()
+	assertions, err := s.Solve()
+	if err != nil {
+		return nil, err
+	}
+
+	return assertions, nil
+}
+
+// Install returns the assertions necessary in order to install the packages in
+// a system.
+// It calculates the best result possible, trying to maximize new packages.
+func (s *Solver) Install(c pkg.Packages) (PackagesAssertions, error) {
+	assertions, err := s.RelaxedInstall(c)
+	if err != nil {
+		return nil, err
+	}
+
+	systemAfterInstall := pkg.NewInMemoryDatabase(false)
+
+	toUpgrade := pkg.Packages{}
+
+	for _, p := range c {
+		if p.GetVersion() == ">=0" || p.GetVersion() == ">0" {
+			toUpgrade = append(toUpgrade, p)
+		}
+	}
+	for _, p := range assertions {
+		if p.Value {
+			systemAfterInstall.CreatePackage(p.Package)
+			if !inPackage(c, p.Package) {
+				toUpgrade = append(toUpgrade, p.Package)
+			}
+		}
+	}
+
+	if len(toUpgrade) == 0 {
+		return assertions, nil
+	}
+	// do partial upgrade based on input.
+	// IF there is no version specified in the input, or >=0 is specified,
+	// then compute upgrade for those
+	_, newassertions, err := s.upgrade(s.computeUpgrade(toUpgrade...), s.DefinitionDatabase, systemAfterInstall, false, false)
+	if err != nil {
+		// TODO: Emit warning.
+		// We were not able to compute upgrades (maybe for some pinned packages, or a conflict)
+		// so we return the relaxed result
+		return assertions, nil
+	}
+
+	// Protect if we return no assertion at all
+	if len(newassertions) == 0 && len(assertions) > 0 {
+		return assertions, nil
+	}
+
+	return newassertions, nil
 }

pkg/solver/solver_test.go

@@ -16,6 +16,8 @@
 package solver_test
 
 import (
+	"fmt"
+
 	pkg "github.com/mudler/luet/pkg/package"
 	. "github.com/onsi/ginkgo"
 	. "github.com/onsi/gomega"
@@ -36,6 +38,143 @@ var _ = Describe("Solver", func() {
 		dbDefinitions = pkg.NewInMemoryDatabase(false)
 		s = NewSolver(Options{Type: SingleCoreSimple}, dbInstalled, dbDefinitions, db)
 	})
+
+	Context("Select of best available package", func() {
+
+		It("picks the best versions available for each package, excluding the ones manually specified while installing", func() {
+
+			B1 := pkg.NewPackage("B", "1.1", []*pkg.DefaultPackage{}, []*pkg.DefaultPackage{})
+			B2 := pkg.NewPackage("B", "1.2", []*pkg.DefaultPackage{}, []*pkg.DefaultPackage{})
+			B3 := pkg.NewPackage("B", "1.3", []*pkg.DefaultPackage{}, []*pkg.DefaultPackage{})
+			B4 := pkg.NewPackage("B", "1.4", []*pkg.DefaultPackage{}, []*pkg.DefaultPackage{})
+
+			A1 := pkg.NewPackage("A", "1.1", []*pkg.DefaultPackage{
+				pkg.NewPackage("B", ">=0", []*pkg.DefaultPackage{}, []*pkg.DefaultPackage{}),
+			}, []*pkg.DefaultPackage{})
+			A2 := pkg.NewPackage("A", "1.2", []*pkg.DefaultPackage{
+				pkg.NewPackage("B", ">=0", []*pkg.DefaultPackage{}, []*pkg.DefaultPackage{}),
+			}, []*pkg.DefaultPackage{})
+
+			D := pkg.NewPackage("D", "1.0", []*pkg.DefaultPackage{
+				pkg.NewPackage("A", ">=0", []*pkg.DefaultPackage{}, []*pkg.DefaultPackage{}),
+			}, []*pkg.DefaultPackage{})
+
+			C := pkg.NewPackage("C", "1", []*pkg.DefaultPackage{}, []*pkg.DefaultPackage{})
+
+			for _, p := range []pkg.Package{A1, A2, B1, B2, B3, B4, C, D} {
+				_, err := dbDefinitions.CreatePackage(p)
+				Expect(err).ToNot(HaveOccurred())
+			}
+
+			for _, p := range []pkg.Package{C} {
+				_, err := dbInstalled.CreatePackage(p)
+				Expect(err).ToNot(HaveOccurred())
+			}
+			s = NewSolver(Options{Type: SingleCoreSimple}, dbInstalled, dbDefinitions, db)
+
+			solution, err := s.(*Solver).Install([]pkg.Package{D})
+			fmt.Println(solution)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(len(solution)).To(Equal(8))
+
+			//	Expect(solution).To(ContainElement(PackageAssert{Package: B, Value: true}))
+			Expect(solution).To(ContainElement(PackageAssert{Package: C, Value: true}))
+			Expect(solution).To(ContainElement(PackageAssert{Package: D, Value: true}))
+			Expect(solution).To(ContainElement(PackageAssert{Package: A2, Value: true}))
+			Expect(solution).To(ContainElement(PackageAssert{Package: B4, Value: true}))
+
+			Expect(solution).To(ContainElement(PackageAssert{Package: A1, Value: false}))
+			Expect(solution).To(ContainElement(PackageAssert{Package: B1, Value: false}))
+			Expect(solution).To(ContainElement(PackageAssert{Package: B2, Value: false}))
+			Expect(solution).To(ContainElement(PackageAssert{Package: B3, Value: false}))
+
+			s = NewSolver(Options{Type: SingleCoreSimple}, dbInstalled, dbDefinitions, db)
+
+			solution, err = s.(*Solver).Install([]pkg.Package{D, B2})
+			fmt.Println(solution)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(len(solution)).To(Equal(8))
+
+			//	Expect(solution).To(ContainElement(PackageAssert{Package: B, Value: true}))
+			Expect(solution).To(ContainElement(PackageAssert{Package: C, Value: true}))
+			Expect(solution).To(ContainElement(PackageAssert{Package: D, Value: true}))
+			Expect(solution).To(ContainElement(PackageAssert{Package: A2, Value: true}))
+			Expect(solution).To(ContainElement(PackageAssert{Package: B2, Value: true}))
+
+			Expect(solution).To(ContainElement(PackageAssert{Package: A1, Value: false}))
+			Expect(solution).To(ContainElement(PackageAssert{Package: B1, Value: false}))
+			Expect(solution).To(ContainElement(PackageAssert{Package: B4, Value: false}))
+			Expect(solution).To(ContainElement(PackageAssert{Package: B3, Value: false}))
+
+		})
+
+		It("picks the best available excluding those manually input. In this case we the input is a selector >=0", func() {
+
+			B1 := pkg.NewPackage("B", "1.1", []*pkg.DefaultPackage{}, []*pkg.DefaultPackage{})
+			B2 := pkg.NewPackage("B", "1.2", []*pkg.DefaultPackage{}, []*pkg.DefaultPackage{})
+			B3 := pkg.NewPackage("B", "1.3", []*pkg.DefaultPackage{}, []*pkg.DefaultPackage{})
+			B4 := pkg.NewPackage("B", "1.4", []*pkg.DefaultPackage{}, []*pkg.DefaultPackage{})
+
+			A1 := pkg.NewPackage("A", "1.1", []*pkg.DefaultPackage{
+				pkg.NewPackage("B", ">=0", []*pkg.DefaultPackage{}, []*pkg.DefaultPackage{}),
+			}, []*pkg.DefaultPackage{})
+			A2 := pkg.NewPackage("A", "1.2", []*pkg.DefaultPackage{
+				pkg.NewPackage("B", ">=0", []*pkg.DefaultPackage{}, []*pkg.DefaultPackage{}),
+			}, []*pkg.DefaultPackage{})
+
+			D := pkg.NewPackage("D", "1.0", []*pkg.DefaultPackage{
+				pkg.NewPackage("A", ">=0", []*pkg.DefaultPackage{}, []*pkg.DefaultPackage{}),
+			}, []*pkg.DefaultPackage{})
+
+			C := pkg.NewPackage("C", "1", []*pkg.DefaultPackage{}, []*pkg.DefaultPackage{})
+
+			for _, p := range []pkg.Package{A1, A2, B1, B2, B3, B4, C, D} {
+				_, err := dbDefinitions.CreatePackage(p)
+				Expect(err).ToNot(HaveOccurred())
+			}
+
+			for _, p := range []pkg.Package{C} {
+				_, err := dbInstalled.CreatePackage(p)
+				Expect(err).ToNot(HaveOccurred())
+			}
+			s = NewSolver(Options{Type: SingleCoreSimple}, dbInstalled, dbDefinitions, db)
+
+			solution, err := s.(*Solver).Install([]pkg.Package{pkg.NewPackage("D", ">=0", []*pkg.DefaultPackage{}, []*pkg.DefaultPackage{})})
+			fmt.Println(solution)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(len(solution)).To(Equal(8))
+
+			//	Expect(solution).To(ContainElement(PackageAssert{Package: B, Value: true}))
+			Expect(solution).To(ContainElement(PackageAssert{Package: C, Value: true}))
+			Expect(solution).To(ContainElement(PackageAssert{Package: D, Value: true}))
+			Expect(solution).To(ContainElement(PackageAssert{Package: A2, Value: true}))
+			Expect(solution).To(ContainElement(PackageAssert{Package: B4, Value: true}))
+
+			Expect(solution).To(ContainElement(PackageAssert{Package: A1, Value: false}))
+			Expect(solution).To(ContainElement(PackageAssert{Package: B1, Value: false}))
+			Expect(solution).To(ContainElement(PackageAssert{Package: B2, Value: false}))
+			Expect(solution).To(ContainElement(PackageAssert{Package: B3, Value: false}))
+
+			s = NewSolver(Options{Type: SingleCoreSimple}, dbInstalled, dbDefinitions, db)
+
+			solution, err = s.(*Solver).Install([]pkg.Package{pkg.NewPackage("D", ">=0", []*pkg.DefaultPackage{}, []*pkg.DefaultPackage{}), B2})
+			fmt.Println(solution)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(len(solution)).To(Equal(8))
+
+			//	Expect(solution).To(ContainElement(PackageAssert{Package: B, Value: true}))
+			Expect(solution).To(ContainElement(PackageAssert{Package: C, Value: true}))
+			Expect(solution).To(ContainElement(PackageAssert{Package: D, Value: true}))
+			Expect(solution).To(ContainElement(PackageAssert{Package: A2, Value: true}))
+			Expect(solution).To(ContainElement(PackageAssert{Package: B2, Value: true}))
+
+			Expect(solution).To(ContainElement(PackageAssert{Package: A1, Value: false}))
+			Expect(solution).To(ContainElement(PackageAssert{Package: B1, Value: false}))
+			Expect(solution).To(ContainElement(PackageAssert{Package: B4, Value: false}))
+			Expect(solution).To(ContainElement(PackageAssert{Package: B3, Value: false}))
+
+		})
+	})
 	Context("Simple set", func() {
 		It("Solves correctly if the selected package has no requirements or conflicts and we have nothing installed yet", func() {