single quotes in run_shower.sh

[BJ]

When doing the showering with Pythia 8, the file run_shower.sh is used. In this script the variable LD_LIBRARY_PATH is modified. Unfortunately this is done using single quotes instead of double quotes. When enclosed by single quotes the variable $LD_LIBRARY_PATH is not expanded. Hence effectively the previous LD_LIBRARY_PATH is removed from the modified LD_LIBRARY_PATH. This leads in my case where I rely on the LD_LIBRARY_PATH to a crash. Strangely this crash does not happen in multicore run (only in single core run). The reason for this I don't know.

[Valentin Hirschi (valentin-hirschi)]

Thanks for this report. There was indeed a bug in the writing of this preamble setting up LD_LIBRARY_PATH and it will be fixed in the next release 2.5.2.

In the meantime you can work around this issue by including yourself the path '<HEPTools_directory_path>/lib' in front of all other paths in your environment variable LD_LIBRARY_PATH. MG5aMC should then detect that it is already there and bypass the writing of this incorrect preamble.