Stable SNAPSHOT Identifiers

When a SNAPSHOT version is deployed to Clojars (or any other Maven repository) it is internally assigned a time-based version identifier. Whenever a new SNAPSHOT is uploaded old SNAPSHOT versions remain available under their time-based version identifier. This can be useful to avoid the pitfalls of using SNAPSHOT versions — changing dependencies without you noticing — while still being able to benefit from the latest and greatest fixes and features.

An Example

Let's assume we have a project clojars/test and deploy a snapshot 0.1.0-SNAPSHOT. Once the deploy is complete the list of versions inside the Maven repository will roughly look like this:

0.1.0-20170205.160151-1
0.1.0-SNAPSHOT (points to the above)

Now a day later we discover a bug in our SNAPSHOT and subsequently release another one:

0.1.0-20170205.160151-1
0.1.0-20170206.170424-1
0.1.0-SNAPSHOT (points to 0.1.0-20170206.170424-1)

In your project.clj or build.boot you can now use any of the below:

[clojars/test "0.1.0-20170205.160151-1"]
[clojars/test "0.1.0-20170206.170424-1"]
[clojars/test "0.1.0-SNAPSHOT"]

If you use 0.1.0-SNAPSHOT your Maven client will check for a new SNAPSHOT release once a day, potentially changing the code of a dependency you are using without you noticing. If you use one of the time-based identifiers there is no automatic updating to watch out for. This of course also means that you need to check for new versions manually.