有人可以帮助我解决此错误吗：

pkg-config --cflags  -- libcryptsetup
Package libcryptsetup was not found in the pkg-config search path.
Perhaps you should add the directory containing `libcryptsetup.pc'
to the PKG_CONFIG_PATH environment variable
No package 'libcryptsetup' found

我的服务器：
红帽企业Linux服务器7.8版（Maipo）

~> rpm -qa | grep cryptsetup
cryptsetup-libs-2.0.3-6.el7.x86_64
cryptsetup-2.0.3-6.el7.x86_64

我不确定如何设置PKG_CONFIG_PATH的ENV变量。
谢谢James