`free --all` fails with confusing message

[nickrobinson251]

(Foobar) pkg> free --all
ERROR: packages may only be specified by name or UUID when calling `free`

Isn't the ERROR message in contradiction with there being a --all flag? I am confused 😊

Seen on Julia v1.11 and nightly (1.13.0-DEV)

The Project.toml looks like

name = "Foobar"
uuid = "469444d5-79b5-4f80-a9af-0769fa2f9410"
authors = [""]
version = "0.1.0"

[preferences.Foobar]
QUX3 = false

[deps]
Example = "7876af07-990d-54b4-ab0e-23690620f79a"
LocalPkg = "fcf55292-0d03-4e8a-9e0b-701580031fc3"
Preferences = "21216c6a-2e73-6563-6e65-726566657250"

[sources]
Example = {url = "https://github.com/JuliaLang/Example.jl"}
LocalPkg = {path = "LocalPkg"}

[KristofferC]

For posterity, this happens because there is a check in free that ensures that one doesn't do something like free Foo#master but this has a bad interaction with sources which will assign e.g. a branch to the package.