How FlakeHub flake URLs work

Here’s the structure of URLs for flakes on FlakeHub:

The version-range segment defines the boundaries of the versions you want. The range isn’t an exact version number but rather a SemVer version constraint, which provides predictable upgrades.

FlakeHub’s version solver behaves like Cargo’s version solver. Here are some example version ranges and how they’re interpreted:

• 1.0.1 is always 1.0.1 and never upgrades to 2.0.0.
• 0.1.1 returns at least 0.1.1 but never upgrades to 0.2.0.

FlakeHub also offers a few comparison operators, which generally shouldn’t be necessary.

Tilde operator (~)

The tilde (~) reduces the maximum version boundary when specifying the major and minor versions. The version constraint ~1.0, for example, upgrades to any version between 1.0 and 1.1 but not to 1.1.

Wildcard operator (*)

The wildcard (*) allows for any version in that position.

• The version range * always uses the highest published version.
• 1.2.* allows any version with the major and minor version 1.2.

Equals operator (=)

The equals (=) operator enables users to specify exactly one version with no room to update.

• =3.2.1 always returns version 3.2.1.