Meson: Get Xgandalf via wrap

1 files changed, 7 insertions, 1 deletions

diff --git a/INSTALL.md b/INSTALL.md
index df4aeccd..7e1be821 100644
--- a/INSTALL.md
+++ b/INSTALL.md
@@ -77,12 +77,18 @@ algorithm.  Provided that FFTW is available, you will also have access to the
 `asdf` algorithm.  The more of the following are additionally installed, the
 better your experience will be:
 
-* [XGandalf](https://stash.desy.de/users/gevorkov/repos/xgandalf)
+* [XGandalf](https://stash.desy.de/users/gevorkov/repos/xgandalf) \[\*\]
 * [PinkIndexer](https://stash.desy.de/users/gevorkov/repos/pinkindexer)
 * [Mosflm](https://www.mrc-lmb.cam.ac.uk/mosflm/mosflm/)
 * [DirAx](http://www.crystal.chem.uu.nl/distr/dirax/)
 * [XDS](http://xds.mpimf-heidelberg.mpg.de/)
 
+As above, if you compile using Meson, dependencies marked with \[\*\] above
+will be downloaded and compiled automatically if they are not available on the
+system.  If you don't want this, add option `--wrap-mode=nofallback` when
+invoking Meson.  See the Meson manual for other possibilities, such as using
+locally-provided files instead of downloading them.
+
 The indexing engines have their own installation instructions.  Mosflm, DirAx
 and XDS can be installed at any time before or after installing CrystFEL, but
 XGandalf and PinkIndexer need to be installed in advance.  If you install them