.flowconfig [version]

You can specify in the .flowconfig which version of Flow you expect to use. You do this with the [version] section. If this section is omitted or left blank, then any version is allowed. If a version is specified and not matched, then Flow will immediately error and exit.

So if you have the following in your .flowconfig:

[version]
0.22.0

and you try to use Flow v0.21.0, then Flow will immediately error with the message

"Wrong version of Flow. The config specifies version 0.22.0 but this is version 0.21.0"

So far, we support the following ways to specify supported versions

• Explicit versions, (e.g. 0.22.0, which only matches 0.22.0).
• Intersection ranges, which are ANDed together, (e.g. >=0.13.0 <0.14.0, which matches 0.13.0 and 0.13.5 but not 0.14.0).
• Caret ranges, which allow changes that do not modify the left-most non-zero digit (e.g. ^0.13.0 expands into >=0.13.0 <0.14.0, and ^0.13.1 expands into >=0.13.1 <0.14.0, whereas ^1.2.3 expands into >=1.2.3 <2.0.0).