`use of internal package not allowed` when trying to build linkerd-tcp example

[vuldin]

Trying to run docker compose build within the linkerd-tcp example results in:

=> ERROR [web0 builder 3/5] RUN go get -d -v github.com/go-redis/redis                                                                                                                                  6.1s
 => [web3 internal] load build context                                                                                                                                                                   0.2s
 => => transferring context: 28B                                                                                                                                                                         0.0s
 => [web8 internal] load build context                                                                                                                                                                   0.2s
 => => transferring context: 28B                                                                                                                                                                         0.0s
 => [web9 internal] load build context                                                                                                                                                                   0.2s
 => => transferring context: 28B                                                                                                                                                                         0.0s
 => [web2 internal] load build context                                                                                                                                                                   0.2s
 => => transferring context: 28B                                                                                                                                                                         0.0s
 => [web1 internal] load build context                                                                                                                                                                   0.2s
 => => transferring context: 28B                                                                                                                                                                         0.0s
 => [web7 internal] load build context                                                                                                                                                                   0.1s
 => => transferring context: 28B                                                                                                                                                                         0.0s
------
 > [web0 builder 3/5] RUN go get -d -v github.com/go-redis/redis:
0.349 github.com/go-redis/redis (download)
2.652 github.com/cespare/xxhash (download)
3.535 github.com/dgryski/go-rendezvous (download)
4.199 github.com/redis/go-redis (download)
6.044 ../../../go-redis/redis/cluster.go:17:2: use of internal package not allowed
6.044 ../../../go-redis/redis/cluster.go:18:2: use of internal package not allowed
6.044 ../../../go-redis/redis/command.go:12:2: use of internal package not allowed
6.044 ../../../go-redis/redis/cluster.go:19:2: use of internal package not allowed
6.044 ../../../go-redis/redis/cluster.go:20:2: use of internal package not allowed
6.044 ../../../go-redis/redis/cluster.go:21:2: use of internal package not allowed
6.044 ../../../go-redis/redis/command.go:14:2: use of internal package not allowed
------
failed to solve: process "/bin/sh -c go get -d -v github.com/go-redis/redis" did not complete successfully: exit code: 1