From c19c25873b2c754dcca17b28702526ace81d6793 Mon Sep 17 00:00:00 2001
From: stefan schippers <stefan.schippers@gmail.com>
Date: Wed, 26 Feb 2025 19:33:14 +0100
Subject: [PATCH] (2)proc to_eng: return arg as is if not valid expression

---
 src/xschem.tcl | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/xschem.tcl b/src/xschem.tcl
index f2688bd2..0c5da912 100644
--- a/src/xschem.tcl
+++ b/src/xschem.tcl
@@ -628,6 +628,10 @@ proc from_eng {i} {
 ## convert number to engineering form
 proc to_eng {args} {
   set suffix {}
+
+  if {[ catch {uplevel #0 expr [join $args]} i]} {
+    return [join $args]
+  }
   set i [uplevel #0 expr [join $args]]
   set absi [expr {abs($i)}]