在Ubuntu 18.04.1上編譯OpenWrt Chaos Calmer的時候碰到了以下問題，記錄一下。

Build dependency: Please install the GNU C Compiler (gcc)
Build dependency: Please reinstall the GNU C Compiler - it appears to be broken
Build dependency: Please install the GNU C++ Compiler (g++)
Build dependency: Please reinstall the GNU C++ Compiler - it
 
 appears to be broken
Build dependency: Please install the Objective Caml compiler (ocaml-nox) v3.12 or later
Build dependency: Please install ncurses. (Missing libncurses.so or ncurses.h)
Build dependency: Please install zlib. (Missing libz.so or zlib.h)
Build dependency: Please install the openssl library (with
 
 development headers)
Build dependency: Please install Python 2.x
Build dependency: Please install the Subversion client
Build dependency: Please install Git (git-core) >= 1.6.5

Build dependency: Please install the GNU C Compiler (gcc)

Build dependency: Please reinstall the GNU C Compiler - it appears to be broken

原因

缺少gcc編譯器

解決方法

安裝gcc編譯器

$ sudo apt-get install gcc

Build dependency: Please install the GNU C++ Compiler (g++)

Build dependency: Please reinstall the GNU C++ Compiler - it appears to be broken

原因

缺少g++編譯器

解決方法

安裝g++編譯器

$ sudo apt-get install g++

Build dependency: Please install the Objective Caml compiler (ocaml-nox) v3.12 or later

原因

缺少ocaml編譯器

解決方法

安裝ocaml編譯器

$ sudo apt-get install ocaml

注：此處用Ubuntu原來的源會碰到錯誤提示“Unable to locate package ocaml”，更換為阿里雲後正常安裝

Build dependency: Please install ncurses. (Missing libncurses.so or ncurses.h)

原因

缺少libncurses.so

解決方法

安裝libncurses.so

$ sudo apt-get install libncurses5-dev

Build dependency: Please install zlib. (Missing libz.so or zlib.h)

原因

缺少libz.so

解決方法

安裝libz.so

$ sudo apt-get install zlib1g-dev

Please install the openssl library (with development headers)

原因

缺少openssl庫

解決方法

安裝openssl庫

$ sudo apt-get install libssl-dev

Build dependency: Please install Python 2.x

原因

缺少Python 2

解決方法

安裝Python 2

$ sudo apt-get install python

Build dependency: Please install the Subversion client

原因

缺少subversion

解決方法

安裝subversion

$ sudo apt-get install subversion

Build dependency: Please install Git (git-core) >= 1.6.5

原因一

缺少git

解決方法

安裝git

$ sudo apt-get install git

注：如果已經安裝git但是仍然收到該錯誤提示，請參考原因二，如果沒有請忽略原因二。

原因二

已經安裝git，但是版本是2.x

檢視git版本
$ git --version
git version 2.17.1

由於對git版本的檢測方式有缺陷導致，OpenWRT已經在 2016-03-05 21:07提交（4c80909fa141fe2921c62bd17b2b04153031df18）中修復該問題

解決方法

請參考https://github.com/openwrt/openwrt/commit/4c80909fa141fe2921c62bd17b2b04153031df18 修改檔案 include/prereq-build.mk 中git版本的判斷命令。 我這裡的判斷命令依然是 git clone 2>&1 | grep – –recursive))， 將其修改為 git –exec-path | xargs -I % – grep -q – –recursive %/git-submodule))

    $(eval $(call SetupHostCommand,git,Please install Git (git-core) >= 1.7.12.2, \
  -     git clone 2>&1 | grep -- --recursive))
  +     git --exec-path | xargs -I % -- grep -q -- --recursive %/git-submodule))