1. go mod tidy : dial tcp xx:443: i/o timeout，
因為go 1.17 默認的GOPROXY=https://proxy.golang.org,direct ，在牆內無法訪問。
所以在.zshrc /.bashrc 加上環境變量
export GOPROXY=https://goproxy.io export GO111MODULE=on
2. go1.17. GoLand 2021.2.3. 因為有些舊的依賴包，不希望啟用go module. 在GOPATH下設置了路徑，把依賴包放到了GOPATH的src下，Go Modules下的Enable Go modules integration也沒打上勾，但go build時報
package common/crypto is not in GOROOT (/usr/local/go/src/common/crypto)
handler.go:4:2: package common/db is not in GOROOT (/usr/local/go/src/common/db)
但GOPATH已設置， 而且也沒啟用module模式
go env GO111MODULE 發現是auto，想改成off，用命令
go env -w GO111MODULE=off
但下面出了警告
warning: go env -w GO111MODULE=... does not override conflicting OS environment variable
在GoLand的控制台打go env GO111MODULE 發現還是auto，但在mac的控制台下go env GO111MODULE 是off
此時要把module模式改成off們需要在.zshrc上加上
export GO111MODULE=off
3.如果本地有個common module，希望引入本地common, 需要加
cd common
go mod init common
cd hallServer
go mod edit -replace common=../common
go mod tidy
表示common這個module就是../common
此時打開go.mod, 有一條common是個虛擬的版本號
5 require ( 6 common v0.0.0-00010101000000-000000000000 7 github.com/gin-gonic/gin v1.7.4 8 )
4. go 1.17.
問題描述:
common 包要依賴github.com/jb00007 ，但在common包 go mod tidy時
common/tcp imports github.com/jb00007/common/log: cannot find module providing package github.com/jb00007/common/log: module github.com/jb00007/common/log: git ls-remote -q origin in /Users/gaoxianghu/go/pkg/mod/cache/vcs/48e703907eff3f5c3f402971dfd15fbaf97b52b1b7cf00f1fdb40daa9dac5325: exit status 128: fatal: could not read Username for 'https://github.com': terminal prompts disabled Confirm the import path was entered correctly. If this is a private repository, see https://golang.org/doc/faq#git_https for additional information. common/tcp imports github.com/jb00007/common/util: cannot find module providing package github.com/jb00007/common/util: module github.com/jb00007/common/util: git ls-remote -q origin in /Users/gaoxianghu/go/pkg/mod/cache/vcs/48e703907eff3f5c3f402971dfd15fbaf97b52b1b7cf00f1fdb40daa9dac5325: exit status 128: fatal: could not read Username for 'https://github.com': terminal prompts disabled Confirm the import path was entered correctly. If this is a private repository, see https://golang.org/doc/faq#git_https for additional information. common/jbcoder tested by common/jbcoder.test imports github.com/jb00007/common/tcp: cannot find module providing package github.com/jb00007/common/tcp: module github.com/jb00007/common/tcp: git ls-remote -q origin in /Users/gaoxianghu/go/pkg/mod/cache/vcs/48e703907eff3f5c3f402971dfd15fbaf97b52b1b7cf00f1fdb40daa9dac5325: exit status 128: fatal: could not read Username for 'https://github.com': terminal prompts disabled Confirm the import path was entered correctly. If this is a private repository, see https://golang.org/doc/faq#git_https for additional information. common/tcp tested by common/tcp.test imports github.com/jb00007/common/jbcoder: cannot find module providing package github.com/jb00007/common/jbcoder: module github.com/jb00007/common/jbcoder: git ls-remote -q origin in /Users/gaoxianghu/go/pkg/mod/cache/vcs/48e703907eff3f5c3f402971dfd15fbaf97b52b1b7cf00f1fdb40daa9dac5325: exit status 128: fatal: could not read Username for 'https://github.com': terminal prompts disabled Confirm the import path was entered correctly.
好像是無法在github.com下載 github.com/jb00007 里的東西，只能用本地的jb00007包, 於是
cd jb00007 go mod init github.com/jb00007 go mod tidy cd ../common go mod edit -replace github.com/jb00007=../jb00007 go mod tidy
其中在jb00007中go mod tidy時報：
go: github.com/jb00007/jbserver2/KenoServer imports github.com/googleapis/google-cloud-go/civil: github.com/googleapis/google-cloud-go@v0.97.0: parsing go.mod: module declares its path as: cloud.google.com/go but was required as: github.com/googleapis/google-cloud-go
但對common的go mod tidy沒影響，所以也沒管這個問題，但當我 到hallServer下執行go mod tidy時就報下面
cd hallServer
go mod tidy
o: downloading golang.org/x/net v0.0.0-20211008194852-3b03d305991f go mod tidy: error loading go 1.16 module graph: common@v0.0.0-00010101000000-000000000000 requires github.com/jb00007@v0.0.0-00010101000000-000000000000: invalid github.com import path "github.com/jb00007"
If reproducibility with go 1.16 is not needed:
go mod tidy -compat=1.17
這問題是loading了工1.16的module graph，但我是1.17呀，於是照着說明運行 go mod tidy -compat=1.17 就ok了。
========
上面的項目在蹈入Goland時會有很多包沒下下來，可能是因為jb00007 go mod tidy沒有成功的關系,因為jb00007依賴的包找不到。把jb00007目錄刪除，common里引用到jb00007里的代碼先注掉，然后把common 的 mod包引用到jb00007的都刪掉，然后在common下重新go mod tidy,這次成功了。然后把hallServer，pushServer,subGame/zjh,subGame/rummy, subGame/nn,subGame/hhdz重新go mod tidy, go build,成功。重新在Goland打開項目，發現包都可以找到了。
在go mod tidy 時，有時會發生：
subGame/nn imports common/db imports github.com/denisenkom/go-mssqldb imports cloud.google.com/go/civil tested by cloud.google.com/go/civil.test imports github.com/google/go-cmp/cmp loaded from github.com/google/go-cmp@v0.2.0, but go 1.16 would select v0.5.5
可能是在本地找到的低版本的包（go-cmp@v0.2.0），但建議的是更高的版本（go-cmp@v0.5.5），
按照建議執行go mod tidy -go=1.16 && go mod tidy -go=1.17即可
To upgrade to the versions selected by go 1.16: go mod tidy -go=1.16 && go mod tidy -go=1.17 If reproducibility with go 1.16 is not needed: go mod tidy -compat=1.17 For other options, see: https://golang.org/doc/modules/pruning