--- a/mercurial/debugcommands.py	Thu Mar 05 10:24:10 2020 +0100
+++ b/mercurial/debugcommands.py	Thu Mar 05 10:24:45 2020 +0100
@@ -1650,6 +1650,13 @@
     fm.plain(_(b'checking "re2" regexp engine (%s)\n') % re2)
     fm.data(re2=bool(util._re2))
 
+    rust_debug_mod = policy.importrust("debug")
+    if rust_debug_mod is not None:
+        re2_rust = b'installed' if rust_debug_mod.re2_installed else b'missing'
+
+        msg = b'checking "re2" regexp engine Rust bindings (%s)\n'
+        fm.plain(_(msg % re2_rust))
+
     # templates
     p = templater.templatepaths()
     fm.write(b'templatedirs', b'checking templates (%s)...\n', b' '.join(p))

--- a/tests/test-install.t	Thu Mar 05 10:24:10 2020 +0100
+++ b/tests/test-install.t	Thu Mar 05 10:24:45 2020 +0100
@@ -18,6 +18,7 @@
   checking available compression engines (*zlib*) (glob)
   checking available compression engines for wire protocol (*zlib*) (glob)
   checking "re2" regexp engine \((available|missing)\) (re)
+  checking "re2" regexp engine Rust bindings \((installed|missing)\) (re)
   checking templates (*mercurial?templates)... (glob)
   checking default template (*mercurial?templates?map-cmdline.default) (glob)
   checking commit editor... (*) (glob)
@@ -77,6 +78,7 @@
   checking available compression engines (*zlib*) (glob)
   checking available compression engines for wire protocol (*zlib*) (glob)
   checking "re2" regexp engine \((available|missing)\) (re)
+  checking "re2" regexp engine Rust bindings \((installed|missing)\) (re)
   checking templates (*mercurial?templates)... (glob)
   checking default template (*mercurial?templates?map-cmdline.default) (glob)
   checking commit editor... (*) (glob)
@@ -124,6 +126,7 @@
   checking available compression engines (*zlib*) (glob)
   checking available compression engines for wire protocol (*zlib*) (glob)
   checking "re2" regexp engine \((available|missing)\) (re)
+  checking "re2" regexp engine Rust bindings \((installed|missing)\) (re)
   checking templates (*mercurial?templates)... (glob)
   checking default template (*mercurial?templates?map-cmdline.default) (glob)
   checking commit editor... ($TESTTMP/tools/testeditor.exe)
@@ -151,6 +154,7 @@
   checking available compression engines (*zlib*) (glob)
   checking available compression engines for wire protocol (*zlib*) (glob)
   checking "re2" regexp engine \((available|missing)\) (re)
+  checking "re2" regexp engine Rust bindings \((installed|missing)\) (re)
   checking templates (*mercurial?templates)... (glob)
   checking default template (*mercurial?templates?map-cmdline.default) (glob)
   checking commit editor... (c:\foo\bar\baz.exe) (windows !)
@@ -207,6 +211,7 @@
   checking available compression engines (*) (glob)
   checking available compression engines for wire protocol (*) (glob)
   checking "re2" regexp engine \((available|missing)\) (re)
+  checking "re2" regexp engine Rust bindings \((installed|missing)\) (re)
   checking templates ($TESTTMP/installenv/*/site-packages/mercurial/templates)... (glob)
   checking default template ($TESTTMP/installenv/*/site-packages/mercurial/templates/map-cmdline.default) (glob)
   checking commit editor... (*) (glob)
@@ -247,6 +252,7 @@
   checking available compression engines (*) (glob)
   checking available compression engines for wire protocol (*) (glob)
   checking "re2" regexp engine \((available|missing)\) (re)
+  checking "re2" regexp engine Rust bindings \((installed|missing)\) (re)
   checking templates ($TESTTMP/installenv/*/site-packages/mercurial/templates)... (glob)
   checking default template ($TESTTMP/installenv/*/site-packages/mercurial/templates/map-cmdline.default) (glob)
   checking commit editor... (*) (glob)