diff --git a/build_defs/go.build_defs b/build_defs/go.build_defs
index 8de215f..d827277 100644
--- a/build_defs/go.build_defs
+++ b/build_defs/go.build_defs
@@ -1621,9 +1621,10 @@ def _go_pkg_info(name:str, srcs:list, visibility:list, importconfig:str=None, im
     install_flags = ""
     for i in install:
         install_flags += f" -p {i}" if i else " -p ."
+    target = canonicalise(":" + name)
 
     if module and not subrepo:
-        cmd = f'$TOOL m -m {module} {install_flags}'
+        cmd = f'$TOOL m -m {module} -t {target} {install_flags}'
     else:
         # The import path `go tool compile` expects for a binary target (i.e. `-p main`) doesn't match what we expect in
         # the driver response i.e. the package dir. We also don't want to set the package name, as that is something
@@ -1633,7 +1634,7 @@ def _go_pkg_info(name:str, srcs:list, visibility:list, importconfig:str=None, im
             import_path =  _get_import_path("", "")
         else:
             import_path = _get_import_path(package, import_path)
-        cmd = f'$TOOL p -i "{import_path}" -m "{import_path}:$PKG_DIR/{package}.a"'
+        cmd = f'$TOOL p -i "{import_path}" -t "{target}" -m "{import_path}:$PKG_DIR/{package}.a"'
         if subrepo:
             cmd = f"{cmd} -s {subrepo}"
         if module:
diff --git a/tools/driver/packages/packages.go b/tools/driver/packages/packages.go
index 6f7522b..619ba1b 100644
--- a/tools/driver/packages/packages.go
+++ b/tools/driver/packages/packages.go
@@ -214,7 +214,8 @@ func loadPackageInfo(files []string, mode packages.LoadMode) ([]*packages.Packag
 		return nil, err
 	}
 	// N.B. deliberate not to close these here, they happen exactly when needed.
-	whatinputs := plz(append([]string{"query", "whatinputs", "--ignore_unknown" }, files...)...)
+	whatinputs := plz("query", "whatinputs", "--ignore_unknown", "-")
+	whatinputs.Stdin = strings.NewReader(strings.Join(files, "\n"))
 	whatinputs.Stdout = w1
 	args := []string{"query", "deps", "-", "--hidden", "-i", "go_pkg_info", "-i", "go_src"}
 	if (mode & packages.NeedExportFile) != 0 {
@@ -342,7 +343,11 @@ func directoriesToFiles(in []string, includeTests bool) ([]string, error) {
 			if err := filepath.WalkDir(strings.TrimSuffix(x, "/..."), func(path string, d fs.DirEntry, err error) error {
 				if err != nil {
 					return err
-				} else if strings.HasSuffix(path, ".go") && (d.Type()&fs.ModeSymlink) == 0 {
+				}
+				if d.Name() =="plz-out" {
+					return filepath.SkipDir
+				}
+				if strings.HasSuffix(path, ".go") && (d.Type()&fs.ModeSymlink) == 0 {
 					files = append(files, path)
 				}
 				return nil
diff --git a/tools/please_go/packageinfo/packageinfo.go b/tools/please_go/packageinfo/packageinfo.go
index 8e547ac..f8d8784 100644
--- a/tools/please_go/packageinfo/packageinfo.go
+++ b/tools/please_go/packageinfo/packageinfo.go
@@ -20,7 +20,7 @@ import (
 )
 
 // WritePackageInfo writes a series of package info files to the given file.
-func WritePackageInfo(importPath string, srcRoot, importconfig string, imports map[string]string, installPkgs []string, subrepo, module string, w io.Writer) error {
+func WritePackageInfo(importPath, srcRoot, target, importconfig string, imports map[string]string, installPkgs []string, subrepo, module string, w io.Writer) error {
 	// Discover all Go files in the module
 	goFiles := map[string][]string{}
 	module = modulePath(module, importPath)
@@ -63,7 +63,7 @@ func WritePackageInfo(importPath string, srcRoot, importconfig string, imports m
 	pkgs := make([]*packages.Package, 0, len(goFiles))
 	for dir := range goFiles {
 		pkgDir := strings.TrimPrefix(strings.TrimPrefix(dir, srcRoot), "/")
-		pkg, err := createPackage(filepath.Join(importPath, pkgDir), dir, subrepo, module)
+		pkg, err := createPackage(filepath.Join(importPath, pkgDir), dir, target, subrepo, module)
 		if _, ok := err.(*build.NoGoError); ok {
 			continue // Don't really care, this happens sometimes for modules
 		} else if err != nil {
@@ -111,7 +111,7 @@ func WritePackageInfo(importPath string, srcRoot, importconfig string, imports m
 	return e.Encode(pkgs)
 }
 
-func createPackage(pkgPath, pkgDir, subrepo, module string) (*packages.Package, error) {
+func createPackage(pkgPath, pkgDir, target, subrepo, module string) (*packages.Package, error) {
 	if pkgDir == "" || pkgDir == "." {
 		// This happens when we're in the repo root, ImportDir refuses to read it for some reason.
 		path, err := filepath.Abs(pkgDir)
@@ -125,13 +125,13 @@ func createPackage(pkgPath, pkgDir, subrepo, module string) (*packages.Package,
 		return nil, err
 	}
 	bpkg.ImportPath = pkgPath
-	return FromBuildPackage(bpkg, subrepo, module), nil
+	return FromBuildPackage(bpkg, target, subrepo, module), nil
 }
 
 // FromBuildPackage creates a packages Package from a build Package.
-func FromBuildPackage(pkg *build.Package, subrepo, module string) *packages.Package {
+func FromBuildPackage(pkg *build.Package, target, subrepo, module string) *packages.Package {
 	p := &packages.Package{
-		ID:              pkg.ImportPath,
+		ID:              target,
 		Name:            pkg.Name,
 		PkgPath:         pkg.ImportPath,
 		GoFiles:         make([]string, len(pkg.GoFiles)),
diff --git a/tools/please_go/please_go.go b/tools/please_go/please_go.go
index c34de65..c0de7ed 100644
--- a/tools/please_go/please_go.go
+++ b/tools/please_go/please_go.go
@@ -78,12 +78,14 @@ var opts = struct {
 		ImportMap  map[string]string `short:"m" long:"import_map" description:"Existing map of imports"`
 		Subrepo    string            `short:"s" long:"subrepo" description:"Subrepo root that this package is within"`
 		Module     string            `long:"mod" description:"The module this is within, if present"`
+		Target      string            `short:"t" long:"target" description:"The build target for this package"`
 	} `command:"package_info" alias:"p" description:"Creates an info file about a Go package"`
 	ModuleInfo struct {
 		ModulePath   string   `short:"m" long:"module_path" required:"true" description:"Import path of the module in question"`
 		Srcs         string   `long:"srcs" env:"SRCS_SRCS" required:"true" description:"Source files of the module"`
 		ImportConfig string   `long:"importconfig" env:"SRCS_IC" description:"Importconfig file for locating gc export data"`
 		Packages     []string `short:"p" long:"packages" description:"Packages to include in the module"`
+		Target      string            `short:"t" long:"target" description:"The build target for this package"`
 	} `command:"module_info" alias:"m" description:"Creates an info file about a series of packages in a go_module"`
 	Generate struct {
 		SrcRoot          string   `short:"r" long:"src_root" description:"The src root of the module to inspect"`
@@ -177,14 +179,14 @@ var subCommands = map[string]func() int{
 	},
 	"package_info": func() int {
 		pi := opts.PackageInfo
-		if err := packageinfo.WritePackageInfo(pi.ImportPath, pi.Pkg, "", pi.ImportMap, nil, pi.Subrepo, pi.Module, os.Stdout); err != nil {
+		if err := packageinfo.WritePackageInfo(pi.ImportPath, pi.Pkg, pi.Target, "", pi.ImportMap, nil, pi.Subrepo, pi.Module, os.Stdout); err != nil {
 			log.Fatalf("failed to write package info: %s", err)
 		}
 		return 0
 	},
 	"module_info": func() int {
 		mi := opts.ModuleInfo
-		if err := packageinfo.WritePackageInfo(mi.ModulePath, mi.Srcs, mi.ImportConfig, nil, mi.Packages, "", "", os.Stdout); err != nil {
+		if err := packageinfo.WritePackageInfo(mi.ModulePath, mi.Srcs, mi.Target, mi.ImportConfig, nil, mi.Packages, "", "", os.Stdout); err != nil {
 			log.Fatalf("failed to write module info: %s", err)
 		}
 		return 0