diff --git a/tools/rbcrun/host.go b/tools/rbcrun/host.go
index 32afa45..f2fda4e 100644
--- a/tools/rbcrun/host.go
+++ b/tools/rbcrun/host.go
@@ -223,16 +223,6 @@
 	return starlark.NewList(elems)
 }
 
-// propsetFromEnv constructs a propset from the array of KEY=value strings
-func structFromEnv(env []string) *starlarkstruct.Struct {
-	sd := make(map[string]starlark.Value, len(env))
-	for _, x := range env {
-		kv := strings.SplitN(x, "=", 2)
-		sd[kv[0]] = starlark.String(kv[1])
-	}
-	return starlarkstruct.FromStringDict(starlarkstruct.Default, sd)
-}
-
 func log(thread *starlark.Thread, fn *starlark.Builtin, args starlark.Tuple, kwargs []starlark.Tuple) (starlark.Value, error) {
 	sep := " "
 	if err := starlark.UnpackArgs("print", nil, kwargs, "sep?", &sep); err != nil {
@@ -255,12 +245,10 @@
 	return starlark.None, nil
 }
 
-func setup(env []string) {
+func setup() {
 	// Create the symbols that aid makefile conversion. See README.md
 	builtins = starlark.StringDict{
 		"struct":   starlark.NewBuiltin("struct", starlarkstruct.Make),
-		"rblf_cli": structFromEnv(env),
-		"rblf_env": structFromEnv(os.Environ()),
 		// To convert find-copy-subdir and product-copy-files-by pattern
 		"rblf_find_files": starlark.NewBuiltin("rblf_find_files", find),
 		// To convert makefile's $(shell cmd)
@@ -285,11 +273,8 @@
 //   and the name that appears in error messages;
 // * src is an optional source of bytes to use instead of filename
 //   (it can be a string, or a byte array, or an io.Reader instance)
-// * commandVars is an array of "VAR=value" items. They are accessible from
-//   the starlark script as members of the `rblf_cli` propset.
-func Run(filename string, src interface{}, commandVars []string) error {
-	setup(commandVars)
-
+func Run(filename string, src interface{}) error {
+	setup()
 	mainThread := &starlark.Thread{
 		Name:  "main",
 		Print: func(_ *starlark.Thread, msg string) { fmt.Println(msg) },
diff --git a/tools/rbcrun/host_test.go b/tools/rbcrun/host_test.go
index 97f6ce9..e109c02 100644
--- a/tools/rbcrun/host_test.go
+++ b/tools/rbcrun/host_test.go
@@ -53,8 +53,8 @@
 }
 
 // Common setup for the tests: create thread, change to the test directory
-func testSetup(t *testing.T, env []string) *starlark.Thread {
-	setup(env)
+func testSetup(t *testing.T) *starlark.Thread {
+	setup()
 	thread := &starlark.Thread{
 		Load: func(thread *starlark.Thread, module string) (starlark.StringDict, error) {
 			if module == "assert.star" {
@@ -72,14 +72,16 @@
 func dataDir() string {
 	_, thisSrcFile, _, _ := runtime.Caller(0)
 	return filepath.Join(filepath.Dir(thisSrcFile), "testdata")
-
 }
 
 func exerciseStarlarkTestFile(t *testing.T, starFile string) {
 	// In order to use "assert.star" from go/starlark.net/starlarktest in the tests, provide:
 	//  * load function that handles "assert.star"
 	//  * starlarktest.DataFile function that finds its location
-	setup(nil)
+	setup()
+	if err := os.Chdir(dataDir()); err != nil {
+		t.Fatal(err)
+	}
 	thread := &starlark.Thread{
 		Load: func(thread *starlark.Thread, module string) (starlark.StringDict, error) {
 			if module == "assert.star" {
@@ -98,26 +100,9 @@
 	}
 }
 
-func TestCliAndEnv(t *testing.T) {
-	// TODO(asmundak): convert this to use exerciseStarlarkTestFile
-	if err := os.Setenv("TEST_ENVIRONMENT_FOO", "test_environment_foo"); err != nil {
-		t.Fatal(err)
-	}
-	thread := testSetup(t, []string{"CLI_FOO=foo"})
-	if _, err := starlark.ExecFile(thread, "cli_and_env.star", nil, builtins); err != nil {
-		if err, ok := err.(*starlark.EvalError); ok {
-			t.Fatal(err.Backtrace())
-		}
-		t.Fatal(err)
-	}
-}
-
 func TestFileOps(t *testing.T) {
 	// TODO(asmundak): convert this to use exerciseStarlarkTestFile
-	if err := os.Setenv("TEST_DATA_DIR", dataDir()); err != nil {
-		t.Fatal(err)
-	}
-	thread := testSetup(t, nil)
+	thread := testSetup(t)
 	if _, err := starlark.ExecFile(thread, "file_ops.star", nil, builtins); err != nil {
 		if err, ok := err.(*starlark.EvalError); ok {
 			t.Fatal(err.Backtrace())
@@ -128,7 +113,7 @@
 
 func TestLoad(t *testing.T) {
 	// TODO(asmundak): convert this to use exerciseStarlarkTestFile
-	thread := testSetup(t, nil)
+	thread := testSetup(t)
 	thread.Load = func(thread *starlark.Thread, module string) (starlark.StringDict, error) {
 		if module == "assert.star" {
 			return starlarktest.LoadAssertModule()
@@ -148,8 +133,5 @@
 }
 
 func TestShell(t *testing.T) {
-	if err := os.Setenv("TEST_DATA_DIR", dataDir()); err != nil {
-		t.Fatal(err)
-	}
 	exerciseStarlarkTestFile(t, "testdata/shell.star")
 }
diff --git a/tools/rbcrun/rbcrun/rbcrun.go b/tools/rbcrun/rbcrun/rbcrun.go
index 4db6a0b..8dd0f46 100644
--- a/tools/rbcrun/rbcrun/rbcrun.go
+++ b/tools/rbcrun/rbcrun/rbcrun.go
@@ -20,44 +20,25 @@
 	"go.starlark.net/starlark"
 	"os"
 	"rbcrun"
-	"strings"
 )
 
 var (
-	execprog = flag.String("c", "", "execute program `prog`")
 	rootdir  = flag.String("d", ".", "the value of // for load paths")
-	file     = flag.String("f", "", "file to execute")
 	perfFile = flag.String("perf", "", "save performance data")
 )
 
 func main() {
 	flag.Parse()
-	filename := *file
-	var src interface{}
-	var env []string
+	filename := ""
 
-	rc := 0
 	for _, arg := range flag.Args() {
-		if strings.Contains(arg, "=") {
-			env = append(env, arg)
-		} else if filename == "" {
+		if filename == "" {
 			filename = arg
 		} else {
 			quit("only one file can be executed\n")
 		}
 	}
-	if *execprog != "" {
-		if filename != "" {
-			quit("either -c or file name should be present\n")
-		}
-		filename = "<cmdline>"
-		src = *execprog
-	}
 	if filename == "" {
-		if len(env) > 0 {
-			fmt.Fprintln(os.Stderr,
-				"no file to run -- if your file's name contains '=', use -f to specify it")
-		}
 		flag.Usage()
 		os.Exit(1)
 	}
@@ -75,7 +56,8 @@
 		}
 	}
 	rbcrun.LoadPathRoot = *rootdir
-	err := rbcrun.Run(filename, src, env)
+	err := rbcrun.Run(filename, nil)
+	rc := 0
 	if *perfFile != "" {
 		if err2 := starlark.StopProfile(); err2 != nil {
 			fmt.Fprintln(os.Stderr, err2)
diff --git a/tools/rbcrun/testdata/cli_and_env.star b/tools/rbcrun/testdata/cli_and_env.star
deleted file mode 100644
index d6f464a..0000000
--- a/tools/rbcrun/testdata/cli_and_env.star
+++ /dev/null
@@ -1,11 +0,0 @@
-# Tests rblf_env access
-load("assert.star", "assert")
-
-
-def test():
-    assert.eq(rblf_env.TEST_ENVIRONMENT_FOO, "test_environment_foo")
-    assert.fails(lambda: rblf_env.FOO_BAR_BAZ, ".*struct has no .FOO_BAR_BAZ attribute$")
-    assert.eq(rblf_cli.CLI_FOO, "foo")
-
-
-test()
diff --git a/tools/rbcrun/testdata/file_ops.star b/tools/rbcrun/testdata/file_ops.star
index 2ee78fc..b2b907c 100644
--- a/tools/rbcrun/testdata/file_ops.star
+++ b/tools/rbcrun/testdata/file_ops.star
@@ -1,22 +1,21 @@
 # Tests file ops builtins
 load("assert.star", "assert")
 
-
 def test():
     myname = "file_ops.star"
     files = rblf_wildcard("*.star")
     assert.true(myname in files, "expected %s in  %s" % (myname, files))
-    files = rblf_wildcard("*.star", rblf_env.TEST_DATA_DIR)
+    files = rblf_wildcard("*.star")
     assert.true(myname in files, "expected %s in %s" % (myname, files))
     files = rblf_wildcard("*.xxx")
     assert.true(len(files) == 0, "expansion should be empty but contains %s" % files)
     mydir = "testdata"
     myrelname = "%s/%s" % (mydir, myname)
-    files = rblf_find_files(rblf_env.TEST_DATA_DIR + "/../", "*")
+    files = rblf_find_files("../", "*")
     assert.true(mydir in files and myrelname in files, "expected %s and %s in %s" % (mydir, myrelname, files))
-    files = rblf_find_files(rblf_env.TEST_DATA_DIR + "/../", "*", only_files=1)
+    files = rblf_find_files("../", "*", only_files=1)
     assert.true(mydir not in files, "did not expect %s in %s" % (mydir, files))
     assert.true(myrelname in files, "expected %s  in %s" % (myrelname, files))
-    files = rblf_find_files(rblf_env.TEST_DATA_DIR + "/../", "*.star")
+    files = rblf_find_files("../", "*.star")
     assert.true(myrelname in files, "expected %s in %s" % (myrelname, files))
 test()
diff --git a/tools/rbcrun/testdata/shell.star b/tools/rbcrun/testdata/shell.star
index ad10697..dd17375 100644
--- a/tools/rbcrun/testdata/shell.star
+++ b/tools/rbcrun/testdata/shell.star
@@ -1,5 +1,5 @@
 # Tests "queue" data type
 load("assert.star", "assert")
 
-assert.eq("load.star shell.star", rblf_shell("cd %s && ls -1 shell.star load.star 2>&1" % rblf_env.TEST_DATA_DIR))
-assert.eq("shell.star", rblf_shell("cd %s && echo shell.sta*" % rblf_env.TEST_DATA_DIR))
+assert.eq("load.star shell.star", rblf_shell("ls -1 shell.star load.star 2>&1"))
+assert.eq("shell.star", rblf_shell("echo shell.sta*"))