Unable to locate package libX11-dev

Question

I was trying to build HTK using Ubuntu 11.04.

These are the commands I used:

sudo ./configure 
make all

I immediately get the error:

X11/Xlib.h: No such file or directory

So when I try to install libX11-dev by using:

sudo apt-get install libX11-dev

I got the following error:

Unable to locate package libX11-dev

I'd appreciate some help on this.

Solution

That's because the file is named libx11-dev

synaptic would be a good thing to have installed & to use for such activities

Comments

[phenomenon]

Is this true for present versions of OS (e.g. Ubuntu 16.04 or 17.04)?

[doug]

the name remains the same

[Fabien Snauwaert]

For anyone who didn't see it right away, the difference is in the case (all lowercase letters.) And if this doesn't help, this thread might.