Why doesn't mkdir create a folder?

Question

linux

mkdir returns -1 for some reason.
If you remove homedir->str and write the path yourself, then everything works.

//check if dir exists
    struct stat st = {0};

    GString* homedir = g_string_new(NULL);
    g_string_append(homedir, getenv("HOME"));
    g_string_append(homedir, ".some/qwe");

    printf("%s", homedir->str);

    if (stat(&homedir->str, &st) == -1) {
        int res= mkdir(homedir->str, 0777);
    }

Answer 1

mkdir returns -1 for some reason

errno? perror? didn't hear?
Does it work with nested directories?
g_string_append(homedir, getenv("HOME"));
g_string_append(homedir, ".some/qwe");
there is no slash between $HOME and .some/qwe.

Answer 2

1. Do you have rights to the folder where you create the file? on whose behalf the script is being run, does this user have write permissions?
2. If mkdir is run from a chroot environment of some kind, it can be replaced by another utility.