OsmoGSMTester: Explain patchelf is used sometimes to modify RPATH
Change-Id: I7bb811bc984c8d576984b038b391cf8130cc465e
diff --git a/doc/manuals/chapters/intro.adoc b/doc/manuals/chapters/intro.adoc
index 6e377da..55f1a5e 100644
--- a/doc/manuals/chapters/intro.adoc
+++ b/doc/manuals/chapters/intro.adoc
@@ -385,7 +385,11 @@
Also, the binaries from a trial are never installed system-wide, but are run
with a specific 'LD_LIBRARY_PATH' pointing at the trial's 'inst', so that
-several trials can run consecutively without conflicting binary versions.
+several trials can run consecutively without conflicting binary versions. For
+some specific binaries which require extra permissions (such as osmo-bts-octphy
+requiring 'CAP_NET_RAW'), 'patchelf' program is used to modify the binary
+'RPATH' field instead because the OS dynamic linker skips 'LD_LIBRARY_PATH' for
+binaries with special permissions.
Once a test suite run is complete, all its reserved resources are torn down (if
the test scripts have not done so already), and the reservations are released