Cannot create Reactor object with clone=True

[sevyharris]

I'm trying to make a PFR from a chain of CSTRs according to this example https://cantera.org/dev/examples/python/reactors/surf_pfr_chain.html but it fails when I try to make the IdealGasReactor, giving me this error:

---------------------------------------------------------------------------
CanteraError                              Traceback (most recent call last)
Cell In[5], line 1
----> 1 r = ct.IdealGasReactor(gas, energy='off')

File build/python/cantera/reactor.pyx:22, in cantera.reactor.ReactorBase.__cinit__()

CanteraError: 
*******************************************************************************
CanteraError thrown by getElementWeight:
element not found: T
*******************************************************************************

I can set clone=False to silence the error, but then later it gives me trouble creating the upstream Reservoir. I have also tried deleting the problem elements listed in the yaml file, but eventually it complains about X and at that point I'd have to change the whole yaml file to use Pt specifically which is not something I want to do.

Steps to reproduce

This is the code I'm running (mechanism attached below):

import cantera as ct

# import the phase models and set the initial conditions
yaml_file = './chem_4p0.yaml'
surf = ct.Interface(yaml_file, 'surface1')
gas = surf.adjacent['gas']

r = ct.IdealGasReactor(gas, energy='off')

# r = ct.IdealGasReactor(gas, energy='off', clone=False)

On 4.0.0a1: run as is
On 3.2.0: set clone=True

Behavior

Cantera crashes when I try to make the IdealGasReactor, which is surprising because this mechanism worked fine for me on Cantera 3.2.0 and older, but I also wasn't using clone=True back then.

System information

• Cantera version: 4.0.0a1, commit d13048d
• OS: Ubuntu 24.04.4 LTS
• Python/MATLAB/other software versions: Python 3.14.3

Attachments
This is my mechanism file:
chem_4p0.yaml

Additional context
This mechanism was generated in RMG and then converted to Cantera using the ck2yaml executable.