新装windows10 专业版（ 21H1  19043.1288 ）遇到 msys2 不能正常启动问题。现象是

 通过windows命令行到 c:/msys2/ 执行
"msys2_shell.cmd -defterm -here"

会提示以下信息：

output logs:bash: /dev/null: No such device or address
bash: /dev/null: No such device or address
bash: /dev/null: No such device or address
bash: /dev/null: No such device or address
/usr/bin/pacman-key: line 535: /dev/null: No such device or address
/usr/share/makepkg/util/message.sh: line 28: /dev/null: No such device or address
/usr/bin/pacman-key: line 599: /dev/null: No such device or address
==> ERROR: Cannot find the gpg binary required for all pacman-key operations.
/usr/bin/pacman-key: line 535: /dev/null: No such device or address
/usr/share/makepkg/util/message.sh: line 28: /dev/null: No such device or address
/usr/bin/pacman-key: line 599: /dev/null: No such device or address
==> ERROR: Cannot find the gpg binary required for all pacman-key operations.
/usr/bin/pacman-key: line 535: /dev/null: No such device or address
/usr/share/makepkg/util/message.sh: line 28: /dev/null: No such device or address
/usr/bin/pacman-key: line 599: /dev/null: No such device or address
==> ERROR: Cannot find the gpg binary required for all pacman-key operations.
gpgconf: Fatal: failed to open '/dev/null': No such device or address
gpgconf: error running '/usr/bin/gpg-connect-agent': exit status 2
gpgconf: error running '/usr/bin/gpg-connect-agent KILLDIRMNGR': General error
gpgconf: Fatal: failed to open '/dev/null': No such device or address
gpgconf: error running '/usr/bin/gpg-connect-agent': exit status 2
gpgconf: error running '/usr/bin/gpg-connect-agent scd killscd': General error
gpgconf: Fatal: failed to open '/dev/null': No such device or address
gpgconf: error running '/usr/bin/gpg-connect-agent': exit status 2
gpgconf: error running '/usr/bin/gpg-connect-agent KILLAGENT': General error
... 

经确认是 windows 的 null 设备启动不正常。

问题可能是以下原因：

c:/window/system32/driver/null.sys  文件问题

笔者解决办法：从其他正常机器复制一个 null.sys 文件 覆盖本地文件（也可以先删旧文件，再复制过来）。

如果换null.sys文件后 sc start null命令执行能看到 图中所示 Running 的情况。

说明null设备启动正常，再去启动msys2.exe程序将正常运行。

参考 null.sys文件，需要使用的可以下载（自测能用，需要的可以下载）

链接：https://pan.baidu.com/s/199xWgWTkS_ZPJIfkeiG_Xw 
提取码：f8jz