Srtool failed within the release workflow

[sameh-farouk]

Describe the bug

Srtool failed within the release workflow with this error

║ 🧰 Substrate Runtime Toolbox - srtool v0.16.0 🧰
  ║ - by Chevdor -
  info: override toolchain for '/build' set to '1.81.0-x86_64-unknown-linux-gnu'
  ║ 🏗 Building tfchain-runtime as release using rustc 1.81.0 (eeb90cda1 2024-09-04)
  ║ ⏳ That can take a little while, be patient... subsequent builds may be faster.
  ║ Since you have to wait a little, you may want to learn more about Substrate runtimes:
  ║ https://docs.substrate.io/learn/architecture/
  ║ Updating crates.io index
  ║ Updating git repository `[https://github.com/paritytech/polkadot-sdk`](https://github.com/paritytech/polkadot-sdk%60)
  ║ Updating git repository `[https://github.com/encointer/substrate-fixed.git`](https://github.com/encointer/substrate-fixed.git%60)
  ║ Updating git repository `[https://github.com/pendulum-chain/substrate-stellar-sdk`](https://github.com/pendulum-chain/substrate-stellar-sdk%60)
  ║ Updating git repository `[https://github.com/w3f/ring-vrf`](https://github.com/w3f/ring-vrf%60)
  ║ error: no matching package named `bandersnatch_vrfs` found
  ║ location searched: https://github.com/w3f/ring-vrf?rev=3119f51#3119f51b
  ║ required by package `sp-core v21.0.0 (https://github.com/paritytech/polkadot-sdk?tag=polkadot-v1.1.0#f60318f6)`
  ║ ... which satisfies git dependency `sp-core` (locked to 21.0.0) of package `tfchain v2.9.2 (/build/node)`
  parse error: Invalid numeric literal at line 1, column 4
  Error: Process completed with exit code 4.

[sameh-farouk]

Update:
I was able to reproduce the issue locally using Act for further debugging.
The Srtool-Action, by default, pulls the latest Srtool image, which was recently updated to 1.81.0. This version uses rustc 1.81.0 to build the TFChain runtime. However, TFChain and polkadot-sdk 1.1.0, which we're currently using, were tested with rustc 1.70.0. The last known working Srtool version from our actions log is 1.77.0.

We should probably pin this version for now, as we are not up to date with polkadot-sdk upstream.

[sameh-farouk]

Update:
PR awaiting review

[sameh-farouk]

Verified,
CI finished, TFChain runtime built and 2.9.2 release created.