Issue verifying AdminUpgradabilityProxy with Buidler Plugin

:1234: Code to reproduce

hi @abcoathup, @frangio

I have similar issues in verifying the Proxy contract too in Avalanche fuji testnet, I'm using snowtrace explorer.
Im using buidler plugin to deploy upgradable proxy contracts.
This is the proxy contract I need help with. I was able to locate the Artifacts folder under @openzepplin/upgrades-core where the byte code from json matches with my bytecode for this contract.

Contract Address 0x6f35706e3af91ce262f63d9060d53be17bb889b4 | SnowTrace
But unable to verify it.
Logic Contract: 0x2EEFE768041Cad8339E4c0E0107386c696d51DeB
Admin Contract: 0x4A9A4f0aA310c39C3693ACdD02f8901E905daeA1.

It would be great help if you guide me.

:computer: Environment

"@openzeppelin/buidler-upgrades": "1.2.1",
"@openzeppelin/upgrades": "2.8.0",
"@nomiclabs/buidler": "1.4.8",
"@nomiclabs/buidler-etherscan": "2.1.0",

I think I need the original proxy contracts & the solc version with optimization details to reproduce the same bytecode & verify using hardhat, as I tried contracts from upgrades/proxy with different versions of solc, that doesn't reproduce the same bytecode as in the artifacts folder of "upgrades-core"

Have you seen this post? The solc JSON input for verification of proxies is included:

Hi @frangio ,

Thanks for the response, I did see the post, but issue for me is I'm using buidler to deploy which is older and it deploys the prebuilt artifacts and it doesn't have code/compiler settings, But I'm using hardhat to verify, since Buidler doesn't support avalanche.|

And for this purpose I need the settings & code to match the byte code of prebuilt artifacts.
Thanks again for the response

Ok I see. In that case you should check out the code for our last Buidler plugin release: @openzeppelin/buidler-upgrades@1.2.2, compile the proxies under packages/core, and use the build info to verify on Snowtrace.