麻烦加上 export LUA_INCLUDE_DIR=$LUAJIT_INC 试试

xiaocang
echo $LUA_INCLUDE_DIR

/usr/local/LuaJIT/include/luajit-2.0

还是不行.

checking for LuaJIT 2.x ... not found
./configure: error: unsupported LuaJIT version; ngx_http_lua_module requires LuaJIT 2.x.

LuaJIT 我是这样安装的,不知道有没有问题/

cd LuaJIT-2.0.5
make install PREFIX=/usr/local/LuaJIT

/usr/local/LuaJIT$ ls
bin include lib share

#define LUAJIT_VERSION "LuaJIT 2.0.5"
#define LUAJIT_VERSION_NUM 20005 /* Version 2.0.5 = 02.00.05. */
#define LUAJIT_VERSION_SYM luaJIT_version_2_0_5

我看到你用的 luajit2-2.1-20201027.tar.gz 这个源码包，但是 $LUA_INCLUDE_DIR 的输出结果是

$ echo $LUA_INCLUDE_DIR
/usr/local/LuaJIT/include/luajit-2.0

麻烦再确认下，你编译安装后的 luajit 的头文件在哪个目录

xiaocang 这个我刚刚看issue的时候注意到了，发现路径错误了，是2.1（就如我最早echo的2.1），但是改成2.1也报同样的错误。
`
echo $LUAJIT_LIB
/usr/local/lib

echo $LUAJIT_INC
/usr/local/include/luajit-2.1

echo $LUA_INCLUDE_DIR
/usr/local/include/luajit-2.1

pwd
/usr/local/include/luajit-2.1

ls
lauxlib.h luaconf.h lua.h lua.hpp luajit.h lualib.h

`

./configure --prefix=/usr/local/nginx --sbin-path=/usr/local/nginx/nginx --conf-path=/usr/local/nginx/nginx.conf --pid-path=/usr/local/nginx/nginx.pid --error-log-path=/usr/local/nginx/logs/error.log --with-ld-opt="-Wl,-rpath,/usr/local/lib" --add-module=/usr/local/src/ngx_devel_kit-0.3.1 --add-module=/usr/local/src/lua-nginx-module-0.10.19

错误依然是这样：
adding module in /usr/local/src/lua-nginx-module-0.10.19
checking for LuaJIT 2.x ... not found
./configure: error: unsupported LuaJIT version; ngx_http_lua_module requires LuaJIT 2.x.

#define OPENRESTY_LUAJIT

#define LUAJIT_VERSION		"LuaJIT 2.1.0-beta3"
#define LUAJIT_VERSION_NUM	20100  /* Version 2.1.0 = 02.01.00. */
#define LUAJIT_VERSION_SYM	luaJIT_version_2_1_0_beta3
#define LUAJIT_COPYRIGHT	"Copyright (C) 2005-2020 Mike Pall"
#define LUAJIT_URL		"https://luajit.org/"

xiaocang

export LUAJIT_LIB=/usr/local/LuaJIT/lib
export LUAJIT_INC=/usr/local/LuaJIT/include/luajit-2.1

这样配置并不起作用，测试了一下还是走else，走auto-discovery
我自己手动改了config，写死了路就可以了。

LUAJIT_INC=/usr/local/LuaJIT/include/luajit-2.1
LUAJIT_LIB=/usr/local/LuaJIT/lib

xiaocang
编译成功后，启动失败。

sudo ./nginx
nginx: [alert] failed to load the 'resty.core' module (https://github.com/openresty/lua-resty-core); ensure you are using an OpenResty release from https://openresty.org/en/download.html (reason: module 'resty.core' not found:
        no field package.preload['resty.core']
        no file './resty/core.lua'
        no file '/usr/local/LuaJIT/share/luajit-2.1.0-beta3/resty/core.lua'
        no file '/usr/local/share/lua/5.1/resty/core.lua'
        no file '/usr/local/share/lua/5.1/resty/core/init.lua'
        no file '/usr/local/LuaJIT/share/lua/5.1/resty/core.lua'
        no file '/usr/local/LuaJIT/share/lua/5.1/resty/core/init.lua'
        no file './resty/core.so'
        no file '/usr/local/lib/lua/5.1/resty/core.so'
        no file '/usr/local/LuaJIT/lib/lua/5.1/resty/core.so'
        no file '/usr/local/lib/lua/5.1/loadall.so'
        no file './resty.so'
        no file '/usr/local/lib/lua/5.1/resty.so'
        no file '/usr/local/LuaJIT/lib/lua/5.1/resty.so'
        no file '/usr/local/lib/lua/5.1/loadall.so') in /usr/local/nginx/nginx.conf:117

niloay i also meet this situation