src/cmd/go/testdata/script/mod_get_issue56494.txt

# Regression test for https://go.dev/issue/56494:
# 'go get' in module mode was failing to prune out dependencies
# through modules whose versions are too low to be selected.

# Initially, modules "a", "b", and "c" are unrelated.
#
# The package import graph at v1 of everything looks like:
#
# m --- a
# |
# + --- b
# |
# + --- c
#
# At v2, package "a" adds imports of "b" and "c"
# (and a requirement on "c" v2):
#
# a --- b
# |
# + --- c
#
# And "b" adds an import of "a/sub" (in module "a"):
#
# b --- a/sub
#
# At v3, "a" no longer imports (nor requires) "c":
#
# a --- b

# So upgrading to a3 adds a dependency on b2,
# b2 adds a dependency on a2 (for "a/sub"),
# and a2 (but not a3) would add a dependency on c2.
# Since a2 is lower than a3 it cannot possibly be selected when
# upgrading to a3: normally a2 is pruned out of a3's module graph,
# so 'go get' should prune it out too, and c should remain at c1
# without error.

go get a@v0.3.0

go list -m c
stdout '^c v0.1.0 '

-- go.mod --
module m

go 1.19

require (
	a v0.1.0
	b v0.1.0
	c v0.1.0
)

replace (
	a v0.1.0 => ./a1
	a v0.2.0 => ./a2
	a v0.3.0 => ./a3
	b v0.1.0 => ./b1
	b v0.2.0 => ./b2
	c v0.1.0 => ./c1
	c v0.2.0 => ./c2
)
-- m.go --
package m

import (
	_ "a"
	_ "b"
	_ "c"
)
-- a1/go.mod --
module a

go 1.19
-- a1/a.go --
package a
-- a2/go.mod --
module a

go 1.19

require (
	b v0.1.0
	c v0.2.0
)
-- a2/a.go --
package a

import (
	_ "b"
	_ "c"
)
-- a2/sub/sub.go --
package sub
-- a3/go.mod --
module a

go 1.19

require b v0.2.0
-- a3/a.go --
package a

import _ "b"
-- a3/sub/sub.go --
package sub
-- b1/go.mod --
module b

go 1.19
-- b1/b.go --
package b
-- b2/go.mod --
module b

go 1.19

require a v0.2.0
-- b2/b.go --
package b

import "a/sub"
-- c1/go.mod --
module c

go 1.19
-- c1/c.go --
package c
-- c2/go.mod --
module c

go 1.19
-- c2/c.go --
package c