Update: It ssems like changing

.secret(secret.secretId())

to

.secret(secret.getId())

fixes the issue for me. It seems pretty weird though... Furthermore,

getId()

is deprecated and changing it to

id()

results in a

java.lang.NoSuchMethodError: 'com.pulumi.core.Output com.pulumi.gcp.secretmanager.Secret.id()'

error being thrown...