can't install php-devel on centos

Rather than running yum install php-devel you needed to run yum --enablerepo=remi,remi-php54 install php-devel .

In short, just specifying which php-devel version you wanted from the remi repo. In your case you had php54 installed from remi so you needed to add in "remi-php54" . That would have successfully installed php-devel without the downtime.

What I did was:

yum search php53

and it showed the php-devel file to install. Once I did the search and found the correct devel package, I simply copied and pasted the entire name after yum install. I executed

yum install php53-devel.x86_64

to get it

If you have php 5.5.x, centos 6.5 64 try this

yum install php55w-devel

You will need also gcc

yum install gcc.x86_64