-bash: ./flume: No such file or directory BUT flume is there and works elsewhere

You can get this message if flume exists but its “loader” doesn't exist, where

• the loader of a native executable is its dynamic loader, for example /lib/ld-linux.so.2;
• the loader of a script is the program mentioned on its shebang line, e.g., /bin/sh if the script begins with #!/bin/sh.

In your case, it looks like you don't have the 32-bit dynamic loader installed on the 64-bit Ubuntu system. It's in the libc6-i386 package.

strings ./flume | head -n 1 will display the path to the dynamic loader that flume requires. This is one of those rare cases where strace ./flume is completely unhelpful.

I consider this situation to be Unix's most misleading error message. Unfortunately fixing it would be hard: the kernel can only report a numeric error code to the caller of the program, so it only has room for “command not found” and not for the name of the loader it's looking for.