Hi guilers, here's a short bash session. Why would the first bash call to "guile s.scm" work, but not the second one? guile-3.0.7 on ubuntu. ============================ $ cat s.scm (format #t "~f\n" 2.5) $ guile s.scm ;;; note: auto-compilation is enabled, set GUILE_AUTO_COMPILE=0 ;;; or pass the --no-auto-compile argument to disable. ;;; compiling /home/chris/s.scm ;;; compiled /home/chris/.cache/guile/ccache/3.0-LE-8-4.5/home/chris/s.scm.go 2.5 $ guile s.scm Backtrace: In ice-9/boot-9.scm: 1752:10 6 (with-exception-handler _ _ #:unwind? _ # _) In unknown file: 5 (apply-smob/0 #) In ice-9/boot-9.scm: 724:2 4 (call-with-prompt ("prompt") # …) In ice-9/eval.scm: 619:8 3 (_ #(#(#))) In ice-9/boot-9.scm: 2835:4 2 (save-module-excursion #) 4380:12 1 (_) In unknown file: 0 (simple-format #t "~f\n" 2.5) ERROR: In procedure simple-format: In procedure simple-format: FORMAT: Unsupported format option ~f - use (ice-9 format) instead $ guile --version guile (GNU Guile) 3.0.7 Packaged by Debian (3.0.7-deb+3.0.7-1) Copyright (C) 2021 Free Software Foundation, Inc. License LGPLv3+: GNU LGPL 3 or later . This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. ============================