Can't run old Algorand devnet anymore

[DanBurton]

I used to be able to run this:

$ REACH_VERSION=2604daf0 REACH_CONNECTOR_MODE=ALGO reach devnet

And it would work fine. But at some point I did a reach update and now it doesn't work, even though I'm specifying the same (old) version as before. It just says this over and over again:

/start.sh: line 11: : Name does not resolve
/start.sh: line 11: /dev/tcp//5432: Invalid argument
not ready yet, trying again in 1s...

[DanBurton]

Context

There was a change in Reach's algorand devnet where we moved the postgres db inside of the devnet Docker image, instead of relying on it as a separate Docker image. Unfortunately, this has hampered one's ability to run old devnets.

There are three versioned things to understand about what's going on here:

1. the version of one's reach script
2. the version of one's reachsh/reach-cli Docker image
3. the version of one's reachsh/devnet-algo Docker image

For #1, you can pull an old version of the reach script directly off of github, though this is likely unnecessary. See, for example: https://github.com/reach-sh/reach-lang/blob/2604daf0/reach

As for #s 2 and 3, you can see their version by calling reach hashes.

$ REACH_VERSION=2604daf0 reach hashes
reach-cli: a9f7613d
...
devnet-algo: 2604daf0

Notice how, for me, reach-cli did not indicate the same hash. That is because reach-cli always uses its :latest version.

Solutions

There are two ways to work around this issue:

just run a newer version of the devnet

Newer versions of the Algorand devnet may still be compatible with your smart contracts, even if they were compiled with an older reach version.

retag reachsh/reach-cli:latest to use an older version

You can manually retag reach-cli:latest to force it to use its older version like so:

REACH_VERSION=2604daf0 # or whatever your desired version is
docker pull "reachsh/reach-cli:$REACH_VERSION"
docker tag "reachsh/reach-cli:$REACH_VERSION" reachsh/reach-cli:latest

(This will be undone if you reach update)

[jeapostrophe]

"may still be compatible" --- Algorand has never implemented a backwards incompatible change and doesn't intend to. New devotes should always be compatible or it will be very very bad for Algorand.

[DanBurton]

Tangential but related: we at Reach are reworking the Reach command-line application in a way that will avoid this kind of problem in future versions.

[DanBurton]

@jeapostrophe I agree.

However, the reach-provided devnets of a given version also have parity with the Reach stdlib's newTestAccount and fundFromFaucet functionality (when the stdlib version matches). Sometimes the faucet account gets changed across versions, which causes backwards-incompatibilities only in regards to this particular faucet-related functionality.

But even in this case, one can use the stdlib's setFaucet functionality in order to override the old stdlib's expected faucet with the newer devnet's actual faucet.