What it means. Two or more dot-imported packages export the same identifier. A dot import (import . "path") drops every exported name of the package into the current file’s namespace; when two of them supply the same name, the generated Go contains two declarations of that identifier and Go rejects it with “redeclared in this block”.
The check needs at least two dot imports to run, and considers every exported name the analyzer knows about: GALA types (including sealed-variant companions), functions, companion objects, and the exports of dot-imported Go packages. It runs early in transformation, before any expression is transformed.
The shortest real case needs no fixture packages at all. concurrent re-exports go_interop’s execution-context helpers as a convenience facade, so dot-importing both is always a collision:
package main
import (
. "martianoff/gala/concurrent"
. "martianoff/gala/go_interop"
)
func main() {
Println("hi")
}
error[GALA-E0032]: dot-import symbol collision(s) detected:
- symbol "Cancel" is exported by multiple dot-imported packages: concurrent, go_interop
- symbol "CancelToken" is exported by multiple dot-imported packages: concurrent, go_interop
- symbol "ExecutionContext" is exported by multiple dot-imported packages: concurrent, go_interop
- symbol "FixedPoolExecutionContext" is exported by multiple dot-imported packages: concurrent, go_interop
- symbol "GlobalEC" is exported by multiple dot-imported packages: concurrent, go_interop
- symbol "IsCancelled" is exported by multiple dot-imported packages: concurrent, go_interop
- symbol "NewCancelToken" is exported by multiple dot-imported packages: concurrent, go_interop
- symbol "NewFixedPoolEC" is exported by multiple dot-imported packages: concurrent, go_interop
- symbol "NewSingleThreadEC" is exported by multiple dot-imported packages: concurrent, go_interop
- symbol "SetGlobalEC" is exported by multiple dot-imported packages: concurrent, go_interop
- symbol "SingleThreadExecutionContext" is exported by multiple dot-imported packages: concurrent, go_interop
- symbol "Spawn" is exported by multiple dot-imported packages: concurrent, go_interop
- symbol "UnboundedExecutionContext" is exported by multiple dot-imported packages: concurrent, go_interop
Use a qualified or aliased import for one of the packages to resolve the conflict.
(Some stdlib packages intentionally re-export names from another package as a convenience facade — e.g. `concurrent` re-exports `go_interop`'s execution-context helpers — so dot-importing both is never meaningful. Pick the facade you want.)
--> main.gala:3:1
|
3 | import (
| ^^^^^^ qualify or alias one of the dot-imports to disambiguate
|
= hint: qualify or alias one of the dot-imports to disambiguate
Every colliding symbol is listed, one bullet per name, sorted, with the packages that supply it. The caret points at the import block rather than a single import, because the collision is a property of the set.
Your own packages report the same way. Two packages that each export Greet, both dot-imported:
error[GALA-E0032]: dot-import symbol collision(s) detected:
- symbol "Greet" is exported by multiple dot-imported packages: pkg_a, pkg_b
Use a qualified or aliased import for one of the packages to resolve the conflict.
(Some stdlib packages intentionally re-export names from another package as a convenience facade — e.g. `concurrent` re-exports `go_interop`'s execution-context helpers — so dot-importing both is never meaningful. Pick the facade you want.)
--> main.gala:3:1
|
3 | import (
| ^^^^^^ qualify or alias one of the dot-imports to disambiguate
|
= hint: qualify or alias one of the dot-imports to disambiguate
Demote one of the dot imports to a qualified import and prefix its uses:
package main
import (
. "example.com/demo/pkg_a"
"example.com/demo/pkg_b"
)
func main() {
Println(Greet()) // pkg_a, via the dot import
Println(pkg_b.Greet()) // pkg_b, explicitly qualified
}
An alias works too when you want both short:
import (
. "example.com/demo/pkg_a"
b "example.com/demo/pkg_b"
)
When the two packages are a facade and the package it re-exports — concurrent and go_interop — the answer is simpler: pick one. Dot-importing both is never meaningful.
Without this check the collision surfaced from go build, against generated code, naming a file the author never wrote. Detecting it at the GALA level names the symbol, names every package that supplies it, and points at the import block that has to change. It was previously reported as an uncoded semantic error; the stable code lets tooling distinguish an import conflict from other semantic failures.
Scope. Dot imports only. A qualified import can never collide, because its names live behind the package selector. A collision between a dot-imported name and a local declaration is not flagged here — local declarations shadow dot imports by design.