diff --git a/Test.hs b/Test.hs
index 7b784d661d..29f891dc4e 100644
--- a/Test.hs
+++ b/Test.hs
@@ -1574,10 +1574,13 @@ test_crypto = do
   where
 	gpgcmd = Utility.Gpg.mkGpgCmd Nothing
 	testscheme scheme = do
-		gpgtmp <- (</> "gpgtest") <$> absPath tmpdir
+		abstmp <- absPath tmpdir
+		testscheme' scheme abstmp
+	testscheme' scheme abstmp = intmpclonerepo $ whenM (Utility.Path.inPath (Utility.Gpg.unGpgCmd gpgcmd)) $ do
+		-- Use a relative path to avoid too long path to gpg's
+		-- agent socket.
+		gpgtmp <- (</> "gpgtmp") <$> relPathCwdToFile abstmp
 		createDirectoryIfMissing False gpgtmp
-		testscheme' scheme gpgtmp
-	testscheme' scheme gpgtmp = intmpclonerepo $ whenM (Utility.Path.inPath (Utility.Gpg.unGpgCmd gpgcmd)) $ do
 		Utility.Gpg.testTestHarness gpgtmp gpgcmd 
 			@? "test harness self-test failed"
 		Utility.Gpg.testHarness gpgtmp gpgcmd $ do
diff --git a/doc/bugs/tests_fail___40__gpg-agent_related__63____41___when_running_build_inside_singularity_container/comment_2_c61b14b76cf06c0b10257c1a84d9478a._comment b/doc/bugs/tests_fail___40__gpg-agent_related__63____41___when_running_build_inside_singularity_container/comment_2_c61b14b76cf06c0b10257c1a84d9478a._comment
new file mode 100644
index 0000000000..1e96fe5d50
--- /dev/null
+++ b/doc/bugs/tests_fail___40__gpg-agent_related__63____41___when_running_build_inside_singularity_container/comment_2_c61b14b76cf06c0b10257c1a84d9478a._comment
@@ -0,0 +1,17 @@
+[[!comment format=mdwn
+ username="joey"
+ subject="""comment 2"""
+ date="2020-03-26T16:55:30Z"
+ content="""
+Tried to reproduce it here running in a directory with the same lenth, but
+no failures. It could have to do with the old version of gpg-agent.
+
+(I don't see how gpg inside the container could talk to gpg-agent outside
+the container at all, unless the container shares a filesystem, and even
+then, gpg inside the container is being run with a nonstandard home
+directory, so it will not try to talk to a gpg-agent socket in the usual
+home directory.)
+
+I have a patch that makes the path to the socket file relative, but can't
+verify if it will fix the problem. I've applied it anyway.
+"""]]