Logging cannot be used early #10937
Description
Trying to use ILOG in ui_attach_impl results in an assertion error:
nvim: ../src/nvim/os/env.c:737: vim_getenv: Assertion `get_vim_var_str(VV_PROGPATH)[0] != NUL' failed.
(gdb) bt
#0 0x00007f7e213d6755 in raise () from /usr/lib/libc.so.6
#1 0x00007f7e213c1851 in abort () from /usr/lib/libc.so.6
#2 0x00007f7e213c1727 in __assert_fail_base.cold () from /usr/lib/libc.so.6
#3 0x00007f7e213cf026 in __assert_fail () from /usr/lib/libc.so.6
#4 0x000055b93a6e4a8d in vim_getenv (name=0x55b93a8df4c0 <log_file_path> "")
at ../src/nvim/os/env.c:737
#5 0x000055b93a6e4337 in expand_env_esc (srcp=0x55b93a827ba2 "$NVIM_LOG_FILE",
dst=0x55b93a8df4c0 <log_file_path> "", dstlen=4095, esc=false, one=false,
prefix=0x0) at ../src/nvim/os/env.c:482
#6 0x000055b93a6e4040 in expand_env (src=0x55b93a827ba2 "$NVIM_LOG_FILE",
dst=0x55b93a8df4c0 <log_file_path> "", dstlen=4096) at ../src/nvim/os/env.c:397
#7 0x000055b93a669972 in log_path_init () at ../src/nvim/log.c:70
#8 0x000055b93a669d15 in open_log_file () at ../src/nvim/log.c:188
#9 0x000055b93a669b4b in logmsg (log_level=1, context=0x0,
func_name=0x55b93a854468 <__func__.18603> "ui_attach_impl", line_num=282,
eol=true, fmt=0x55b93a8543d1 "ui_attach_impl") at ../src/nvim/log.c:133
#10 0x000055b93a7b4317 in ui_attach_impl (ui=0x55b93ac4f480) at ../src/nvim/ui.c:282
#11 0x000055b93a7b7809 in ui_comp_init () at ../src/nvim/ui_compositor.c:86
#12 0x000055b93a7b3d42 in ui_init () at ../src/nvim/ui.c:109
#13 0x000055b93a672525 in event_init () at ../src/nvim/main.c:157
#14 0x000055b93a6726d8 in main (argc=11, argv=0x7ffc96522ac8)
at ../src/nvim/main.c:260
From a quick look it seems like this could skip using VV_PROGPATH /
v:progpath then.
But of course there might be better ways to fix this ("logging should be usable as early as possible").