The CRA, in technical interpretation 2018-0776661I7 (August 8, 2019), takes the position that a Bitcoin miner receives Bitcoin as barter for services rendered. The transaction is a barter transaction because Bitcoin isn’t legal tender (see IT-490 “Barter Transactions”). The receipt occurs at the time the Bitcoin is received. The amount to be reported for income tax purposes, if the Bitcoin miner carries on business as such, is probably the value of the Bitcoin at the time of receipt. The technical interpretation states that the Bitcoin value can likely be determined more easily than the value of the services given up in exchange.
The CRA website has a “Guide for cryptocurrency users and tax professionals” here.