[tracker-miners/sam/debug] Document the TRACKER_DEBUG variable in man pages

[Sam Thursfield <sthursfield src gnome org>]

commit ce237c1435d2328bd89bf06fe6b22cd3ae44fa49
Author: Sam Thursfield <sam afuera me uk>
Date:   Mon Apr 20 19:37:11 2020 +0200

    Document the TRACKER_DEBUG variable in man pages
    
    We also now document G_MESSAGES_DEBUG, users might expect some
    kind of `--debug` flag so at least they can discover this if
    they consult the manpage.

 docs/manpages/tracker-extract.1.txt   |  7 +++++++
 docs/manpages/tracker-miner-fs.1.txt  | 11 +++++++++++
 docs/manpages/tracker-miner-rss.1.txt |  7 +++++++
 3 files changed, 25 insertions(+)
---
diff --git a/docs/manpages/tracker-extract.1.txt b/docs/manpages/tracker-extract.1.txt
index 33dd524f9..1a18a2228 100644
--- a/docs/manpages/tracker-extract.1.txt
+++ b/docs/manpages/tracker-extract.1.txt
@@ -35,6 +35,13 @@ Using command line to extract metadata from a file:::
 
 $ tracker extract /path/to/some/file.mp3
 
+== ENVIRONMENT
+
+*G_MESSAGES_DEBUG*::
+  Controls verbose log output from GLib-based code. Use
+  `G_MESSAGES_DEBUG=Tracker` to see only Tracker-related
+  logs, or `G_MESSAGES_DEBUG=all` to see everything.
+
 == SEE ALSO
 
 *tracker-sparql*(1), *tracker-stats*(1), *tracker-info*(1).
diff --git a/docs/manpages/tracker-miner-fs.1.txt b/docs/manpages/tracker-miner-fs.1.txt
index 70ec7e87f..d1f5a656f 100644
--- a/docs/manpages/tracker-miner-fs.1.txt
+++ b/docs/manpages/tracker-miner-fs.1.txt
@@ -39,6 +39,17 @@ than one instance of this at the same time.
   would be monitored for changes. This works with non-existing *FILE*
   arguments as well as existing *FILE* arguments.
 
+== ENVIRONMENT
+
+*G_MESSAGES_DEBUG*::
+  Controls verbose log output from GLib-based code. Use
+  `G_MESSAGES_DEBUG=Tracker` to see only Tracker-related
+  logs, or `G_MESSAGES_DEBUG=all` to see everything.
+*TRACKER_DEBUG*::
+  Enables more specialized debug output. Pass a comma-separated
+  list of one or more keywords:
+    miner-fs-events::: log processing of file-system changes
+
 == SEE ALSO
 
 *tracker-info*(1).
diff --git a/docs/manpages/tracker-miner-rss.1.txt b/docs/manpages/tracker-miner-rss.1.txt
index 8500d8a25..5a7e4f56a 100644
--- a/docs/manpages/tracker-miner-rss.1.txt
+++ b/docs/manpages/tracker-miner-rss.1.txt
@@ -39,6 +39,13 @@ You can use *tracker-search --feeds* to get the latest feed information.
 *-t, --title=STRING*::
   The title to use when adding a feed (see the *--add-feed* option).
 
+== ENVIRONMENT
+
+*G_MESSAGES_DEBUG*::
+  Controls verbose log output from GLib-based code. Use
+  `G_MESSAGES_DEBUG=Tracker` to see only Tracker-related
+  logs, or `G_MESSAGES_DEBUG=all` to see everything.
+
 == SEE ALSO
 
 *tracker-info*(1), *tracker-search*(1).