+ The new
+ GOPRIVATE
+ environment variable indicates module paths that are not publicly available.
+ It contains a comma-separated list of glob patterns (in the syntax of
+ path.Match) to be matched against a
+ prefix of the module path. It serves as the default value for the
+ lower-level GONOPROXY and GONOSUMDB variables, which
+ provide finer-grained control over which modules are fetched via proxy and
+ verified using the checksum database.
+
+ The GOPROXY
+ environment variable may now be set to a comma-separated list of proxy
+ URLs or the special token direct, and
+ its default value is
+ now https://proxy.golang.org,direct. When resolving a package
+ path to its containing module, the go command will try each
+ possible module path on the first proxy in the list before falling back to the
+ next. If an HTTPS proxy is unreachable or returns a status code other than 404
+ or 410 for a given module path, no subsequent proxy is consulted for that
+ path. The direct token indicates that the go command
+ should attempt to fetch the module directly from its origin;
+ GOPROXY entries after direct are ignored.
+
+ The new
+ GOSUMDB
+ environment variable identifies the name, and optionally the public key and
+ server URL, of the database to consult for checksums of modules that are not
+ yet listed in the main module's go.sum file.
+ If GOSUMDB does not include an explicit URL, the URL is chosen by
+ probing the GOPROXY URLs for an endpoint indicating support for
+ the checksum database, falling back to a direct connection to the named
+ database if it is not supported by any proxy. If GOSUMDB is set
+ to off, the checksum database is not consulted and only the
+ existing checksums in the go.sum file are verified.
+
+ Users who cannot reach the default proxy and checksum database (for example,
+ due to a firewalled or sandboxed configuration) may disable their use by
+ setting GOPROXY to direct, and/or
+ GOSUMDB to off.
+ go env -w
+ can be used to set the default values for these variables independent of
+ platform:
+
+go env -w GOPROXY=direct +go env -w GOSUMDB=off ++
go get