From 122b297a204437dfccf75b638a555c360a6765f5 Mon Sep 17 00:00:00 2001
From: Nick Mathewson <nickm@torproject.org>
Date: Fri, 18 Sep 2020 15:53:06 -0400
Subject: [PATCH 1/3] Copy tracing things back to maint-0.3.5, for consistency.

---
 .gitlab-ci.yml          | 12 ++++++++++++
 scripts/ci/ci-driver.sh |  5 +++++
 2 files changed, 17 insertions(+)

diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 176c71f8f0..48bcf6b000 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -92,6 +92,7 @@ variables:
     - if [ "$STEM" = yes ]; then git clone --depth 1 https://git.torproject.org/stem.git ; export STEM_PATH="$(pwd)/stem"; fi
     # TODO: This next line should not be debian-only.
     - if [ "$CHUTNEY" = yes ]; then git clone --depth 1 https://git.torproject.org/chutney.git ;  export CHUTNEY_PATH="$(pwd)/chutney"; fi
+    - if [ "$TRACING" = yes ]; then apt install liblttng-ust-dev; fi
 
 # Minmal check on debian: just make, make check.
 #
@@ -155,3 +156,14 @@ debian-integration:
     STEM: "yes"
   script:
     - ./scripts/ci/ci-driver.sh
+
+#####
+# Tracing build on Debian stable.
+debian-tracing:
+  image: debian:stable
+  <<: *debian-template
+  variables:
+    TRACING: "yes"
+    CHECK: "no"
+  script:
+    - ./scripts/ci/ci-driver.sh
diff --git a/scripts/ci/ci-driver.sh b/scripts/ci/ci-driver.sh
index 527bba82e5..cd91a91bbf 100755
--- a/scripts/ci/ci-driver.sh
+++ b/scripts/ci/ci-driver.sh
@@ -33,6 +33,7 @@ COVERAGE="${COVERAGE:-no}"
 RUST="${RUST:-no}"
 DOXYGEN="${DOXYGEN:-no}"
 ASCIIDOC="${ASCIIDOC:-no}"
+TRACING="${TRACING:-no}"
 
 # Options for which tests to run.   All should be yes/no.
 CHECK="${CHECK:-yes}"
@@ -191,6 +192,7 @@ yes_or_no COVERAGE
 yes_or_no RUST
 yes_or_no DOXYGEN
 yes_or_no ASCIIDOC
+yes_or_no TRACING
 
 yes_or_no RUN_STAGE_CONFIGURE
 yes_or_no RUN_STAGE_BUILD
@@ -241,6 +243,9 @@ fi
 if [[ "$ASCIIDOC" != "yes" ]]; then
     configure_options+=("--disable-asciidoc")
 fi
+if [[ "$TRACING" == "yes" ]]; then
+    configure_options+=("--enable-tracing-instrumentation-lttng")
+fi
 
 #############################################################################
 # Tell the user about our versions of different tools and packages.

From f8f3e57016214685a2474342883eb16dfaf22ce1 Mon Sep 17 00:00:00 2001
From: Nick Mathewson <nickm@torproject.org>
Date: Fri, 18 Sep 2020 15:55:02 -0400
Subject: [PATCH 2/3] .gitlab.yml: missing comments

---
 .gitlab-ci.yml | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 48bcf6b000..028a49f52c 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -37,7 +37,7 @@ variables:
     paths:
       - artifacts/
 
-# This template
+# This template should be usable on any system that's based on apt.
 .apt-template: &apt-template |
       export LC_ALL=C.UTF-8
       echo Etc/UTC > /etc/timezone
@@ -54,6 +54,7 @@ variables:
       apt-get update -qq
       apt-get upgrade -qy
 
+# This template sets us up for Debian system in particular.
 .debian-template: &debian-template
   <<: *artifacts-template
   variables:

From 0b77c706a1799d2ee6d8da4737bb7f152140e3c4 Mon Sep 17 00:00:00 2001
From: Nick Mathewson <nickm@torproject.org>
Date: Fri, 18 Sep 2020 15:56:59 -0400
Subject: [PATCH 3/3] Make debian-trace job conditional on
 src/lib/trace/trace_sys.c

---
 .gitlab-ci.yml | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 028a49f52c..ce279a4bce 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -168,3 +168,15 @@ debian-tracing:
     CHECK: "no"
   script:
     - ./scripts/ci/ci-driver.sh
+  # Ensure that we only run tracing when it's implemented.
+  #
+  # Once versions before 0.4.5 are obsolete, we can remove this test.
+  rules:
+    # This first "if" check prevents us from running a duplicate version of
+    # this pipeline whenever we push and create an MR.  I don't understand why
+    # it is necessary, though the following URL purports to explain:
+    #
+    # https://docs.gitlab.com/ee/ci/yaml/#prevent-duplicate-pipelines
+    - if: '$CI_PIPELINE_SOURCE == "push"'
+      exists:
+        - src/lib/trace/trace_sys.c