Makefile.common portability problem

[dveeden]

Bug Report

Makefile.common has this:

EXTENSION_FLAG =
ifeq ($(shell if [ -a extension/enterprise/.git ]; then echo "true"; fi),true)

The problem is that -a isn't supported by [ on FreeBSD and possibly on other platforms as well.

The result is this:

% gmake server
[: -a: unexpected operator
CGO_ENABLED=1 GO111MODULE=on go build  -tags codes  -ldflags '-X "github.com/pingcap/tidb/parser/mysql.TiDBReleaseVersion=v7.1.0-alpha-343-ga02a751b82" -X "github.com/pingcap/tidb/util/versioninfo.TiDBBuildTS=2023-04-25 14:57:28" -X "github.com/pingcap/tidb/util/versioninfo.TiDBGitHash=a02a751b827d1e7eeb1f07e2018ba255e568410b" -X "github.com/pingcap/tidb/util/versioninfo.TiDBGitBranch=master" -X "github.com/pingcap/tidb/util/versioninfo.TiDBEdition=Community" ' -o bin/tidb-server ./tidb-server
go: downloading github.com/prometheus/client_golang v1.15.0
go: downloading github.com/tikv/client-go/v2 v2.0.8-0.20230419123920-35c1ee47c4f9
go: downloading github.com/tikv/pd/client v0.0.0-20230419153320-f1d1a80feb95
go: downloading github.com/pingcap/kvproto v0.0.0-20230419072653-dc3cd8784a19
go: downloading github.com/blacktear23/go-proxyprotocol v1.0.6
go: downloading github.com/prometheus/common v0.42.0
go: downloading google.golang.org/genproto v0.0.0-20230410155749-daa745c078e1
go: downloading cloud.google.com/go/storage v1.30.1
go: downloading github.com/kr/pretty v0.3.1
...

This was introduced in #43095

See also:

• https://man.freebsd.org/cgi/man.cgi?query=test&apropos=0&sektion=0&manpath=FreeBSD+13.2-RELEASE+and+Ports&arch=default&format=html
• https://linux.die.net/man/1/bash ("Conditional Expressions" section)
• https://pubs.opengroup.org/onlinepubs/9699919799/utilities/test.html