Premake5未创建项目必要输出目录，该如何解决？

问题场景 #

Windows系统下使用Premake5作为C项目构建系统，项目包含三个Premake脚本：

1. 根目录 premake5.lua

workspace "epoch"
    configurations { "Debug", "Release", "Dist" }
    architecture "x86_64"
    startproject "sandbox"

include "runtime/runtime.lua"
include "sandbox/sandbox.lua"

2. runtime/runtime.lua

project "runtime"
    kind "SharedLib"
    language "C"

    targetdir "../bin/%{cfg.buildcfg}"
    objdir "../obj/%{cfg.buildcfg}"

    files {
        "runtime/src/**.c",
        "runtime/src/**.h"
    }

    filter "configurations:Debug"
        symbols "On"

    filter "configurations:Release or configurations:Dist"
        optimize "On"

3. sandbox/sandbox.lua

project "sandbox"
    kind "WindowedApp"
    language "C"

    targetdir "../bin/%{cfg.buildcfg}"
    objdir "../obj/%{cfg.buildcfg}"

    files {
        "sandbox/src/**.c",
        "sandbox/src/**.h"
    }

    filter "configurations:Debug"
        symbols "On"

    filter "configurations:Release or configurations:Dist"
        optimize "On"

使用gmake2生成器生成Makefile后，执行make时出现错误：

==== Building runtime (debug) ====
Creating ../bin/Debug
mkdir: cannot create directory '..\\bin\\Debug': No such file or directory
make[1]: *** [Makefile:88: ../bin/Debug] Error 1
make: *** [Makefile:36: runtime] Error 2

原因是mkdir尝试创建../bin/Debug时，上层的bin目录尚未存在，导致创建失败。

解决办法 #

方法1：手动提前创建父目录 #

在项目根目录执行命令，提前创建bin和obj目录：

• 若使用Git Bash/WSL终端：

mkdir bin obj

• 若使用Windows CMD：

md bin obj

方法2：修改Premake脚本，构建时自动创建父目录 #

在根目录的premake5.lua中添加预构建命令，确保在编译前创建必要的父目录：

workspace "epoch"
    configurations { "Debug", "Release", "Dist" }
    architecture "x86_64"
    startproject "sandbox"

    -- 预构建阶段检查并创建bin、obj目录
    prebuildcommands {
        "if not exist bin mkdir bin",
        "if not exist obj mkdir obj"
    }

include "runtime/runtime.lua"
include "sandbox/sandbox.lua"

该命令会在每个项目构建前执行，确保父目录存在，无需手动操作。

方法3：修改Premake脚本，生成Makefile时自动创建目录 #

在根目录premake5.lua开头添加Premake内置的目录创建函数，在生成Makefile的阶段就创建好bin和obj：

-- 生成Makefile时提前创建根目录下的bin、obj文件夹
os.mkdir("bin")
os.mkdir("obj")

workspace "epoch"
    configurations { "Debug", "Release", "Dist" }
    architecture "x86_64"
    startproject "sandbox"

include "runtime/runtime.lua"
include "sandbox/sandbox.lua"

这种方式在执行premake5 gmake2时就会创建目录，避免构建阶段的mkdir错误。

内容的提问来源于stack exchange，提问作者guyus15