Unable to activate virtualenv via bash script

I'm running a project inside a virtualenv in python. Here's the path to the virtualenv.

~/iss/issp/bin

The problem is when I try to run the activate script with:

source activate

it throws the following error.

:~/iss/issp/bin$ source activate
: command not found
bash: activate: line 4: syntax error near unexpected token `$'{\r''
'ash: activate: line 4: `deactivate () {

Here's the code inside the script:

# This file must be used with "source bin/activate" *from bash*
# you cannot run it directly

deactivate () {
    unset pydoc

    # reset old environment variables
    if [ -n "$_OLD_VIRTUAL_PATH" ] ; then
        PATH="$_OLD_VIRTUAL_PATH"
        export PATH
        unset _OLD_VIRTUAL_PATH
    fi
    if [ -n "$_OLD_VIRTUAL_PYTHONHOME" ] ; then
        PYTHONHOME="$_OLD_VIRTUAL_PYTHONHOME"
        export PYTHONHOME
        unset _OLD_VIRTUAL_PYTHONHOME
    fi

    # This should detect bash and zsh, which have a hash command that must
    # be called to get it to forget past commands.  Without forgetting
    # past commands the $PATH changes we made may not be respected
    if [ -n "$BASH" -o -n "$ZSH_VERSION" ] ; then
        hash -r 2>/dev/null
    fi

    if [ -n "$_OLD_VIRTUAL_PS1" ] ; then
        PS1="$_OLD_VIRTUAL_PS1"
        export PS1
        unset _OLD_VIRTUAL_PS1
    fi

    unset VIRTUAL_ENV
    if [ ! "$1" = "nondestructive" ] ; then
    # Self destruct!
        unset -f deactivate
    fi
}

# unset irrelevant variables
deactivate nondestructive

VIRTUAL_ENV="/home/pablo/issp"
export VIRTUAL_ENV

_OLD_VIRTUAL_PATH="$PATH"
PATH="$VIRTUAL_ENV/bin:$PATH"
export PATH

# unset PYTHONHOME if set
# this will fail if PYTHONHOME is set to the empty string (which is bad anyway)
# could use `if (set -u; : $PYTHONHOME) ;` in bash
if [ -n "$PYTHONHOME" ] ; then
    _OLD_VIRTUAL_PYTHONHOME="$PYTHONHOME"
    unset PYTHONHOME
fi

if [ -z "$VIRTUAL_ENV_DISABLE_PROMPT" ] ; then
    _OLD_VIRTUAL_PS1="$PS1"
    if [ "x" != x ] ; then
        PS1="$PS1"
    else
    if [ "`basename \"$VIRTUAL_ENV\"`" = "__" ] ; then
        # special case for Aspen magic directories
        # see http://www.zetadev.com/software/aspen/
        PS1="[`basename \`dirname \"$VIRTUAL_ENV\"\``] $PS1"
    else
        PS1="(`basename \"$VIRTUAL_ENV\"`)$PS1"
    fi
    fi
    export PS1
fi

alias pydoc="python -m pydoc"

# This should detect bash and zsh, which have a hash command that must
# be called to get it to forget past commands.  Without forgetting
# past commands the $PATH changes we made may not be respected
if [ -n "$BASH" -o -n "$ZSH_VERSION" ] ; then
    hash -r 2>/dev/null
fi

Just had the same problem, and decided to do hexdump -C bin/activate to figure out. Turns out my bin/activate file had CR/LF line endings instead of just CR, changing them with (tr -d '\r' < bin/activate) > bin/activatefixed my problem.