asm/errno.h: No such file or directory

I got the same error on ubuntu-xenial 4.4.0-75-generic.

I found I had a /usr/include/asm-generic folder, but no /usr/include/asm, which gcc was looking for.

Creating a symlink solved it for me.

sudo ln -s /usr/include/asm-generic/ /usr/include/asm

Fair warning: Although, sometimes, one has to do this kind of trickery, it's not always a good idea just because it works. I'm doing this in a virtual machine, which I can recreate by running a simple script, and that is why it's no big deal if I break something.

The asm/errno.h header is provided by a variety of packages. Odd that gcc would require it, but you can try:

sudo apt-get install linux-libc-dev

You also need to tell GCC to look for an architecture and OS specific location for the headers:

../configure --build=x86_64-linux-gnu 

(or i386-linux-gnu for 32-bit Ubuntu).

It's highly recommended when building stuff from source that you use --prefix flag (and with GCC, the --program-suffix flag) while configuring. Since you haven't, try running /usr/bin/gcc.

Thus:

tar xf gcc-4.8.1.tar.gz 
mkdir gcc
cd gcc
../gcc-4.8.1/configure  --build=x86_64-linux-gnu --prefix=/usr/local --program-suffix=-4.8.1
make -j
sudo make install

Now your GCC binaries will be installed to /usr/local/bin/, and other things in other folders in /usr/local.

For example:

$ /usr/local/bin/gcc-4.8.1  # or simply gcc-4.8.1, since this folder is in your PATH

Note how I'm running configure and make from a different directory, outside of where the GCC source is? That's how the GCC docs recommend that GCC be built.