[BUG] Segmentation fault when no permission to write files

[duhow]

Describe the bug

Having files without write permission (eg. owned by root, lacking permissions) crashes the app.

Expected output

Show a message error and exit clean.

Current output

write(1, "Parsing file test.asm\n", 22Parsing file test.asm
) = 22
openat(AT_FDCWD, "~tmppre.0", O_WRONLY|O_CREAT|O_TRUNC, 0666) = -1 EACCES (Permiso denegado)
--- SIGSEGV {si_signo=SIGSEGV, si_code=SEGV_MAPERR, si_addr=0xc0} ---
+++ killed by SIGSEGV (core dumped) +++
[1]    223038 segmentation fault (core dumped)  strace ./asmsx-debug test.asm