Bash script: bad interpreter

The first line, #!/bin/bash, tells Linux where to find the interpreter. The script should also be executable with chmod +x script.sh, which it appears you did.

It is highly likely that you created this file with a windows editor, which will place a <cr><lf> at the end of each line. This is the standard under dos / windows. OS X will place a <cr> at the end of each line. However, under Unix / Linux, the standard is to just put a <lf> at the end of the line.

Linux is now looking for a file called /bin/bash<cr> to interpret the file, where <cr> is a carriage return character, which is a valid file character under Linux. Such a file doesn't exist. Hence the error.

Solution: Edit the file with an editor on Linux and get rid of the extra <cr>. One tool that usually works when the file is edited on Windows is dos2unix.

Could the script be using Dos newlines?

Try running dos2unix on it.

It looks like things have been configured to override the export builtin somehow. This can be done via an exported function or the enable builtin, for example. Try putting type export in the script to check. If you are setting BASH_ENV, you probably shouldn't.

If bash is called as sh, it enables POSIX mode and does not allow export to be overridden with a function, as required by POSIX. Likewise, most other shells installed as /bin/sh follow POSIX in this and/or do not allow the execution environment of a script to be messed up so strongly as through importing functions from the environment.

By the way, the script seems designed to be sourced, i.e. . ./mono-2.6-environment instead of ./mono-2.6-environment.

Had the same problem. Used brute force:

/bin/sh /full/path/to/configure --options

& this did the trick

(Of course I'd like to know why)