diff --git a/code/commands.go b/code/commands.go
index b1ea387a..1c63a0d1 100644
--- a/code/commands.go
+++ b/code/commands.go
@@ -126,9 +126,9 @@ func (cm *CmdAndArgs) PrepCmd(avp *ArgVarVals) (*exec.Cmd, string) {
 	switch cm.Cmd {
 	case "{PromptString1}": // special case -- expand args
 		cmdstr := cstr
-		args, err := shellwords.Parse(cmdstr)
-		if err != nil {
-			fmt.Println(err)
+		args := errors.Log1(shellwords.Parse(cmdstr))
+		if len(args) == 0 {
+			return nil, ""
 		}
 		if len(args) > 1 {
 			cstr = args[0]
@@ -482,6 +482,9 @@ func (cm *Command) RunAfterPrompts(cv *Code, buf *texteditor.Buffer) {
 // line of the command output to code statusbar
 func (cm *Command) RunBufWait(cv *Code, buf *texteditor.Buffer, cma *CmdAndArgs) bool {
 	cmd, cmdstr := cma.PrepCmd(&cv.ArgVals)
+	if cmd == nil {
+		return false
+	}
 	cv.RunningCmds.AddCmd(cm.Label(), cmdstr, cma, cmd)
 	out, err := cmd.CombinedOutput()
 	cm.AppendCmdOut(cv, buf, out)
@@ -492,6 +495,9 @@ func (cm *Command) RunBufWait(cv *Code, buf *texteditor.Buffer, cma *CmdAndArgs)
 // buffer with new results line-by-line as they come in
 func (cm *Command) RunBuf(cv *Code, buf *texteditor.Buffer, cma *CmdAndArgs) bool {
 	cmd, cmdstr := cma.PrepCmd(&cv.ArgVals)
+	if cmd == nil {
+		return false
+	}
 	cv.RunningCmds.AddCmd(cm.Label(), cmdstr, cma, cmd)
 	stdout, err := cmd.StdoutPipe()
 	if err == nil {
diff --git a/go.mod b/go.mod
index 4ee3d29c..3fc0985f 100644
--- a/go.mod
+++ b/go.mod
@@ -3,7 +3,7 @@ module cogentcore.org/cogent
 go 1.22
 
 require (
-	cogentcore.org/core v0.3.3-0.20240902172924-b432919e181b
+	cogentcore.org/core v0.3.3-0.20240902213628-48df10901467
 	github.com/aandrew-me/tgpt/v2 v2.7.2
 	github.com/alecthomas/chroma/v2 v2.13.0
 	github.com/bogdanfinn/fhttp v0.5.27
diff --git a/go.sum b/go.sum
index b9efcc64..1b6cbe58 100644
--- a/go.sum
+++ b/go.sum
@@ -1,5 +1,5 @@
-cogentcore.org/core v0.3.3-0.20240902172924-b432919e181b h1:G7CC9jK/8FWCOYrc83VR5raE82xCkTlG3/h63txQ5Pw=
-cogentcore.org/core v0.3.3-0.20240902172924-b432919e181b/go.mod h1:dg3uRsPcd8S1ZYvRD2TztCtjopRkrB5V/lbl54xsQd4=
+cogentcore.org/core v0.3.3-0.20240902213628-48df10901467 h1:AL9pi5H1ttL76EpnqBCCaflNnfwRxuezZOApoSOL564=
+cogentcore.org/core v0.3.3-0.20240902213628-48df10901467/go.mod h1:dg3uRsPcd8S1ZYvRD2TztCtjopRkrB5V/lbl54xsQd4=
 github.com/Bios-Marcel/wastebasket v0.0.4-0.20240213135800-f26f1ae0a7c4 h1:6lx9xzJAhdjq0LvVfbITeC3IH9Fzvo1aBahyPu2FuG8=
 github.com/Bios-Marcel/wastebasket v0.0.4-0.20240213135800-f26f1ae0a7c4/go.mod h1:FChzXi1izqzdPb6BiNZmcZLGyTYiT61iGx9Rxx9GNeI=
 github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=