# Herwig Installation

+ [**Official, Latest** -- herwig-bootstrap manual](https://herwig.hepforge.org/tutorials/installation/bootstrap.html)
> - This is the latest version. ONE IS SUGGESTED TO TRY THIS FIRST.
> - The previous version (7.1.5) has an issue of calling an empty link to the **boost** package, so below a modified version is provided.
+ [**ver 7.1.5** -- herwig-bootstrap modified script](https://www.dropbox.com/s/cujkmow5otpgcwc/herwig-bootstrap?dl=0)
+ Prerequisites:
+ gcc version ≥ 4.8.5: `gcc -v`
+ [For reference] other dependencies can be looked up [here](https://herwig.hepforge.org/tutorials/installation/prerequisite.html#prerequisites)
> - **herwig-bootstrap** script is supposed to collect the dependencies that meet the need of Herwig installation. It should be sufficient and one doesn't need to worry about the dependencies if one has an OK gcc version.
+ Installation (same as the official manual):

    chmod +x herwig-bootstrap
    ./herwig-bootstrap -j 4 <where_to_install_herwig>

Usage (after installed):

    source <where_to_install_herwig>/bin/activate # to set the Herwig environment
    decativate # to leave the Herwig environment

+ Error report:
1. gcc version problem:
> ../../include/ThePEG/Helicity/LorentzSpinor.h:299:40: error: cannot call member function ‘std::complex<_Tp> ThePEG::Helicity::LorentzSpinor< <template-parameter-1-1> >::s2() const [with Value = ThePEG::Qty<0, 1, 0, 1, 2, 1>]’ without object
-> LorentzVector<decltype(fb.s3()*s2())>