Unsure How To Call cregen From TOML Input File

[corinwagen]

Describe the issue
Trying to run the cregen protocol with input.toml, since I thought that CREST was moving to the TOML specification.

To Reproduce
Here's one of the input.toml files I've tried—I've tried different runtypes, to no avail.
input.toml:

input = "geom.xyz"
threads = 8
runtype = "singlepoint"
topo = false

[calculation]
[[calculation.level]]
method = "gfn0"
charge = 0
uhf = "0"

geom.xyz:

14
Butane
C   2.142   1.395  -8.932
C   3.631   1.416  -8.537
C   4.203  -0.012  -8.612
C   5.691   0.009  -8.218
H   1.604   0.760  -8.260
H   1.745   2.388  -8.880
H   2.043   1.024  -9.930
H   4.169   2.051  -9.210
H   3.731   1.788  -7.539
H   3.665  -0.647  -7.940
H   4.104  -0.384  -9.610
H   6.088  -0.983  -8.270
H   5.791   0.381  -7.220
H   6.230   0.644  -8.890

This is what happens when I try to run this:

$ path/to/binaries/crest_3_0_1 input.toml --cregen geom.xyz --ewin 50

       ╔════════════════════════════════════════════╗
       ║            ___ ___ ___ ___ _____           ║
       ║           / __| _ \ __/ __|_   _|          ║
       ║          | (__|   / _|\__ \ | |            ║
       ║           \___|_|_\___|___/ |_|            ║
       ║                                            ║
       ║  Conformer-Rotamer Ensemble Sampling Tool  ║
       ║          based on the xTB methods          ║
       ║                                            ║
       ╚════════════════════════════════════════════╝
       Version 3.0.1, Mon May  6 18:43:33 UTC 2024
       commit (1782d7d) compiled by 'runner@fv-az772-53'

   Cite work conducted with this code as

   • P.Pracht, F.Bohle, S.Grimme, PCCP, 2020, 22, 7169-7192.
   • S.Grimme, JCTC, 2019, 15, 2847-2862.
   • P.Pracht, S.Grimme, C.Bannwarth, F.Bohle, S.Ehlert,
     G.Feldmann, J.Gorges, M.Müller, T.Neudecker, C.Plett,
     S.Spicher, P.Steinbach, P.Wesołowski, F.Zeller,
     J. Chem. Phys., 2024, 160, 114110.

   for works involving QCG cite

   • S.Spicher, C.Plett, P.Pracht, A.Hansen, S.Grimme,
     JCTC, 2022, 18 (5), 3174-3189.
   • C.Plett, S. Grimme,
     Angew. Chem. Int. Ed. 2023, 62, e202214477.

   for works involving MECP screening cite

   • P.Pracht, C.Bannwarth, JCTC, 2022, 18 (10), 6370-6385.

   Original code
     P.Pracht, S.Grimme, Universität Bonn, MCTC
   with help from (alphabetical order):
     C.Bannwarth, F.Bohle, S.Ehlert, G.Feldmann, J.Gorges,
     S.Grimme, C.Plett, P.Pracht, S.Spicher, P.Steinbach,
     P.Wesolowski, F.Zeller

   Online documentation is available at
   https://crest-lab.github.io/crest-docs/

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
   GNU Lesser General Public License (LGPL) for more details.

 Command line input:
 $ /home/corin/peregrine/src/peregrine/utils/binaries/crest_3_0_1 input.toml --cregen geom.xyz --ewin 50

 reading input.toml
 input.toml
 ├── key: input               value: geom.xyz                 type: string
 ├── key: threads             value: 8                        type: integer
 ├── key: runtype             value: singlepoint              type: string
 └── key: topo                value: false                    type: bool
 object: calculation
 object: calculation.level
 ├── key: method              value: gfn0                     type: string
 ├── key: charge              value: 0                        type: integer
 └── key: uhf                 value: 0                        type: string
  --cregen : CREGEN standalone usage. Sorting file <geom.xyz>
  --ewin 50
 Using only the cregen sorting routine.
 Warning, file crest_rotamers_0.xyz does not exist!

Additional context
Trying to follow instructions from here but feeling somewhat confused.

[pprcht]

Most cli and toml options are cross-compatible. However, cregen does not have a runtype defined in the TOML yet, meaning the call is still via the cli and --cregen <ensemble_file>

There is a dedicated [cregen] block for ewin, ethr, bthr, rthr. It seems I haven't documented this in the documentation, but it should be straightforward.