Cannot find yasm even though I have installed it

Question

I got a strange problem. I tried to install x264. When run sudo ./configure --enable-shared, it gave:

Found no assembler Minimum version is yasm-0.7.0 If you really want to compile without asm, configure with --disable-asm.

But I already installed yasm-0.7.0 ,to prove that ,i run yasm --version,it gave:

*yasm 0.7.0.2066 Compiled on May 8 2012. Copyright (c) 2001-2008 Peter Johnson and other Yasm developers. Run yasm --license for licensing overview and summary.*

I install yasm to /usr/local/yasm, Why can it not find yasm?

Answer 1

sudo ignores your PATH environment variable and uses its own.

compare:

$ which yasm
/usr/local/bin/yasm

with:

$ sudo which yasm
/usr/bin/yasm

To solve, do:

$ sudo PATH=$PATH:/usr/local/bin which yasm
/usr/local/bin/yasm

or rather

$ sudo PATH=$PATH:/usr/local/bin ./configure --enable-shared

Answer 2

Just in case of someone got here from Google, looking for a recent solution.

Recent versions of x264 moved from yasm to nasm, hence breaking some FFMPEG install scripts or tutorials. To check if it is the case, look at the output. If it reads

Minimum version is nasm-2.13

then you are to install nasm. In Ubuntu 16.04 repos there's nasm 2.11; so you'll have to build from sources, following official instruction http://www.linuxfromscratch.org/blfs/view/svn/general/nasm.html.