Try #10:

Project.toml

@@ -20,15 +20,17 @@ AWSCore = "0.5.2, 0.6"
 AWSSDK = "0.2, 0.3, 0.4, 0.5"
 AWSTools = "0.3.1, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1"
 AutoHashEquals = "0.2.0"
+Git_jll = "2.27"
 HTTP = "0.8.1"
 Memento = "0.7, 0.8, 0.9, 0.10, 0.11, 0.12, 0.13, 1"
 Mocking = "0.7"
 OrderedCollections = "1.4"
 julia = "1"
 
 [extras]
+Git_jll = "f8c6e375-362e-5223-8a59-34ff63f689eb"
 HTTP = "cd3eb016-35fb-5094-929b-558a96fad6f3"
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 
 [targets]
-test = ["HTTP", "Test"]
+test = ["Git_jll", "HTTP", "Test"]

test/runtests.jl

@@ -6,6 +6,7 @@ using AWSSDK.CloudWatchLogs: get_log_events
 using AWSTools.CloudFormation: stack_output
 using AWSTools.EC2: instance_region
 using Dates
+using Git_jll
 using HTTP: HTTP
 using Memento
 using Memento.TestUtils: @test_log, @test_nolog
@@ -25,9 +26,12 @@ const JOB_TIMEOUT = 900
 const LOG_TIMEOUT = 30
 
 const JULIA_BAKED_IMAGE = let
-    output = read(`git ls-remote --tags https://github.com/JuliaLang/julia`, String)
+    output = git() do git_path
+        read(`$git_path ls-remote --tags https://github.com/JuliaLang/julia`, String)
+    end
     tags = split(replace(output, r".*\/" => ""))
     versions = VersionNumber.(filter(v -> !endswith(v, "^{}"), tags))
+
     latest_version = maximum(versions)
     docker_tag = VERSION > latest_version ? "nightly" : "$VERSION"