rustfmt's `--config-path` help text is misleading

As of 8b0b213cddb23a9bbe421b717d1a0e5fb3982712, the help text is:

$ rustfmt -h
...
        --config-path [Path for the configuration file]
                        Recursively searches the given path for the
                        rustfmt.toml config file. If not found reverts to the
                        input file path

Some points of confusion:

1. How can there be a recursive search if the configure is a "file": [Path for the configuration file]?
   a. It seems like this option can take a directory with rustfmt.toml OR the file itself.
2. When passed a directory, rustfmt does not appear to search recursively for a config file through ancestors or decedent directories:

   $ mkdir -p /tmp/dir1/dir2/dir3
   $ find /tmp/dir1/
   /tmp/dir1/
   /tmp/dir1/dir2
   /tmp/dir1/dir2/dir3
   $ strace target/debug/rustfmt --config-path=/tmp/dir1/dir2/ /dev/null |& rg dir1 -C1
   execve("target/debug/rustfmt", ["target/debug/rustfmt", "--config-path=/tmp/dir1/dir2/", "/dev/null"], 0x7ffc4c2ad340 /* 61 vars */) = 0
   brk(NULL)                               = 0x5607c5058000
   --
   statx(0, NULL, AT_STATX_SYNC_AS_STAT, STATX_ALL, NULL) = -1 EFAULT (Bad address)
   statx(AT_FDCWD, "/tmp/dir1/dir2/", AT_STATX_SYNC_AS_STAT, STATX_ALL, {stx_mask=STATX_ALL|0x1000, stx_attributes=0, stx_mode=S_IFDIR|0775, stx_size=4096, ...}) = 0
   statx(AT_FDCWD, "/tmp/dir1/dir2/", AT_STATX_SYNC_AS_STAT, STATX_ALL, {stx_mask=STATX_ALL|0x1000, stx_attributes=0, stx_mode=S_IFDIR|0775, stx_size=4096, ...}) = 0
   statx(AT_FDCWD, "/tmp/dir1/dir2/.rustfmt.toml", AT_STATX_SYNC_AS_STAT, STATX_ALL, 0x7ffc9118d8b0) = -1 ENOENT (No such file or directory)
   statx(AT_FDCWD, "/tmp/dir1/dir2/rustfmt.toml", AT_STATX_SYNC_AS_STAT, STATX_ALL, 0x7ffc9118d8b0) = -1 ENOENT (No such file or directory)
   write(2, "Error: unable to find a config f"..., 73Error: unable to find a config file for the given path: `/tmp/dir1/dir2/`) = 73
   write(2, "\n", 1
   

3. The last sentence says that if the file is not found, then "reverts to the input file path", but it seems like rustfmt will emit an error when the file does not exist

   rustfmt --config-path=/does/not/exist /dev/null
   Error: unable to find a config file for the given path: `/does/not/exist`
   

Start by locating the rustfmt CLI definition and the help text for --config-path, then reproduce the documented directory, file, and nonexistent-path commands from the issue. Done means the help text accurately describes accepted paths, search behavior, and the error case, with checks covering the reported examples.