While compiling PHP from source on CentOS server, we get the error below:
checking for icu-config... no checking for location of ICU headers and libraries... not found configure: error: Unable to detect ICU prefix or no failed. Please verify ICU install prefix and make sure icu-config works.
You need to install Components for Unicode Development package as follows:
sudo yum -y install libicu-devel
# yum list installed | grep libicu libicu.x86_64 50.2-4.el7_7 @base libicu-devel.x86_64 50.2-4.el7_7 @base
And then try to re-compile PHP from source and it should be able to compile this time.