The following crashes instantly; I used single-quotes by accident. (open-file "/tmp/lg" 'w')
Stack: Enter `,help' for help. scheme@(guile-user)> (open-file "/tmp/lg" 'w') Thread 1 "guile" received signal SIGSEGV, Segmentation fault. scm_i_mode_to_open_flags (mode=mode@entry=0x555555ac5660, is_binary=is_binary@entry=0x7fffffffd46c, FUNC_NAME=FUNC_NAME@entry=0x7ffff7b89a7d "open-file") at ../../libguile/fports.c:168 168 switch (*md) (gdb) bt #0 scm_i_mode_to_open_flags (mode=mode@entry=0x555555ac5660, is_binary=is_binary@entry=0x7fffffffd46c, FUNC_NAME=FUNC_NAME@entry=0x7ffff7b89a7d "open-file") at ../../libguile/fports.c:168 #1 0x00007ffff7b057e9 in scm_open_file_with_encoding ( filename=filename@entry=0x555555b7fd98, mode=mode@entry=0x555555ac5660, guess_encoding=0x4, encoding=0x4) at ../../libguile/fports.c:242 #2 0x00007ffff7b05b83 in scm_i_open_file (filename=0x555555b7fd98, mode=0x555555ac5660, keyword_args=<optimized out>) at ../../libguile/fports.c:380 #3 0x00007ffff7b6a221 in vm_debug_engine (thread=0x555555ac5660, vp=0x555555844f30, registers=0x54aad62357094bc, resume=39) at ../../libguile/vm-engine.c:760 A patch that seems reasonable to me: $ git diff diff --git a/libguile/fports.c b/libguile/fports.c index 8fa69933d..28e666b6a 100644 --- a/libguile/fports.c +++ b/libguile/fports.c @@ -230,6 +230,9 @@ scm_open_file_with_encoding (SCM filename, SCM mode, unsigned int retries; char *file; + if (SCM_UNLIKELY (!scm_is_string (mode))) + scm_wrong_type_arg_msg (FUNC_NAME, 2, mode, "mode to be string"); + if (SCM_UNLIKELY (!(scm_is_false (encoding) || scm_is_string (encoding)))) scm_wrong_type_arg_msg (FUNC_NAME, 0, encoding, "encoding to be string or false");