back.verilog: fix Yosys version check.

diff --git a/nmigen/back/verilog.py b/nmigen/back/verilog.py
index 1e97dd45c991510594062e6d2d973553d749bddc..b1e29a66c2745e8180cc6cebfce6107b71138691 100644 (file)
--- a/nmigen/back/verilog.py
+++ b/nmigen/back/verilog.py
@@ -24,7 +24,7 @@ def _yosys_version():
 def _convert_rtlil_text(rtlil_text, *, strip_internal_attrs=False, write_verilog_opts=()):
     version, offset = _yosys_version()
     if version < (0, 9):
-        raise YosysError("Yosys %d.%d is not suppored", *version)
+        raise YosysError("Yosys %d.%d is not suppored".format(*version))
 
     attr_map = []
     if strip_internal_attrs: