Military prison is unsuitable place for stoner? (10)

I haven't cracked this one yet — but the brilliant team at Times for the Times have:

The cryptic hint refers to the saying “People in glasshouses shouldn’t throw stones”. My AI assistant advises: The term ‘glasshouse’ in this context originated from the Aldershot military prison in the United Kingdom built in 1870. It was designed with a large glass lantern roof, which led to the nickname ‘The Glasshouse’ and over time, the term became synonymous with all military prisons in the UK.