diff --git a/claudetool/testdata/add_skipped_test.txtar b/claudetool/testdata/add_skipped_test.txtar
index 099ebdd..dba6df2 100644
--- a/claudetool/testdata/add_skipped_test.txtar
+++ b/claudetool/testdata/add_skipped_test.txtar
@@ -21,7 +21,7 @@
 -- .run_test --
 # Errors
 
-Test regressions detected between initial commit (2cdfdc5009e364add9a263909472f85eb08480ed) and HEAD:
+Test regressions detected between initial commit (INITIAL_COMMIT_HASH) and HEAD:
 
 1: sketch.dev.TestP: New test is skipped
 
diff --git a/claudetool/testdata/empty_testdir_add_file.txtar b/claudetool/testdata/empty_testdir_add_file.txtar
index 7c2be2d..6b6a1bb 100644
--- a/claudetool/testdata/empty_testdir_add_file.txtar
+++ b/claudetool/testdata/empty_testdir_add_file.txtar
@@ -31,7 +31,7 @@
 -- .run_test --
 # Errors
 
-Test regressions detected between initial commit (cdc9ec6dfb8669c11d8aa0df49c72112627784dc) and HEAD:
+Test regressions detected between initial commit (INITIAL_COMMIT_HASH) and HEAD:
 
 1: sketch.dev.TestEmptyTestdata: Was passing, now failing
 
diff --git a/claudetool/testdata/mark_test_skipped.txtar b/claudetool/testdata/mark_test_skipped.txtar
index d834ae4..17f5168 100644
--- a/claudetool/testdata/mark_test_skipped.txtar
+++ b/claudetool/testdata/mark_test_skipped.txtar
@@ -26,7 +26,7 @@
 -- .run_test --
 # Errors
 
-Test regressions detected between initial commit (851ba0628e0e2d93e27e168d6af336f3e4d375c7) and HEAD:
+Test regressions detected between initial commit (INITIAL_COMMIT_HASH) and HEAD:
 
 1: sketch.dev.TestP: Was passing, now skipped
 
diff --git a/claudetool/testdata/multi_commit_review.txtar b/claudetool/testdata/multi_commit_review.txtar
index cbf2464..5c741ce 100644
--- a/claudetool/testdata/multi_commit_review.txtar
+++ b/claudetool/testdata/multi_commit_review.txtar
@@ -38,7 +38,7 @@
 -- .run_test --
 # Errors
 
-Test regressions detected between initial commit (a4fd3c2166b35e02a2cde466880e45aea6e6212e) and HEAD:
+Test regressions detected between initial commit (INITIAL_COMMIT_HASH) and HEAD:
 
 1: sketch.dev.TestX: New test is failing
 
diff --git a/claudetool/testdata/new_test_build_error.txtar b/claudetool/testdata/new_test_build_error.txtar
index 2405c49..7a9166d 100644
--- a/claudetool/testdata/new_test_build_error.txtar
+++ b/claudetool/testdata/new_test_build_error.txtar
@@ -21,7 +21,7 @@
 -- .run_test --
 # Errors
 
-Test regressions detected between initial commit (cf75ed70e940ce33a17a70b1894ad053b67731c0) and HEAD:
+Test regressions detected between initial commit (INITIAL_COMMIT_HASH) and HEAD:
 
 1: sketch.dev: Previously had no tests, now has build/vet errors
 
diff --git a/claudetool/testdata/no_tests_to_failing_tests.txtar b/claudetool/testdata/no_tests_to_failing_tests.txtar
index 6161586..b15c179 100644
--- a/claudetool/testdata/no_tests_to_failing_tests.txtar
+++ b/claudetool/testdata/no_tests_to_failing_tests.txtar
@@ -21,7 +21,7 @@
 -- .run_test --
 # Errors
 
-Test regressions detected between initial commit (cf75ed70e940ce33a17a70b1894ad053b67731c0) and HEAD:
+Test regressions detected between initial commit (INITIAL_COMMIT_HASH) and HEAD:
 
 1: sketch.dev.TestP: New test is failing
 
diff --git a/claudetool/testdata/passing_to_build_error.txtar b/claudetool/testdata/passing_to_build_error.txtar
index 6c7d1d0..255f26d 100644
--- a/claudetool/testdata/passing_to_build_error.txtar
+++ b/claudetool/testdata/passing_to_build_error.txtar
@@ -26,7 +26,7 @@
 -- .run_test --
 # Errors
 
-Test regressions detected between initial commit (149798f10aaf06bc4700bb62d46ed6d8d88e35ad) and HEAD:
+Test regressions detected between initial commit (INITIAL_COMMIT_HASH) and HEAD:
 
 1: sketch.dev: Was passing, now has build/vet errors
 
diff --git a/claudetool/testdata/passing_to_failing.txtar b/claudetool/testdata/passing_to_failing.txtar
index 50afae7..f96208b 100644
--- a/claudetool/testdata/passing_to_failing.txtar
+++ b/claudetool/testdata/passing_to_failing.txtar
@@ -26,7 +26,7 @@
 -- .run_test --
 # Errors
 
-Test regressions detected between initial commit (149798f10aaf06bc4700bb62d46ed6d8d88e35ad) and HEAD:
+Test regressions detected between initial commit (INITIAL_COMMIT_HASH) and HEAD:
 
 1: sketch.dev.TestP: Was passing, now failing
 
diff --git a/claudetool/testdata/passing_to_failing_subdir.txtar b/claudetool/testdata/passing_to_failing_subdir.txtar
index 1211912..7aaef4a 100644
--- a/claudetool/testdata/passing_to_failing_subdir.txtar
+++ b/claudetool/testdata/passing_to_failing_subdir.txtar
@@ -26,7 +26,7 @@
 -- .run_test --
 # Errors
 
-Test regressions detected between initial commit (8c6c71d0beac5e27b87dfc3f2fd9d274b62c3d3a) and HEAD:
+Test regressions detected between initial commit (INITIAL_COMMIT_HASH) and HEAD:
 
 1: sketch.dev/foo.TestP: Was passing, now failing
 
diff --git a/claudetool/testdata/skipped_to_build_error.txtar b/claudetool/testdata/skipped_to_build_error.txtar
index 671b53b..4bd8642 100644
--- a/claudetool/testdata/skipped_to_build_error.txtar
+++ b/claudetool/testdata/skipped_to_build_error.txtar
@@ -27,7 +27,7 @@
 -- .run_test --
 # Errors
 
-Test regressions detected between initial commit (3635353dfefb2fa652728318567209ccfc4aba42) and HEAD:
+Test regressions detected between initial commit (INITIAL_COMMIT_HASH) and HEAD:
 
 1: sketch.dev: Was passing, now has build/vet errors
 
diff --git a/claudetool/testdata/skipped_to_failing.txtar b/claudetool/testdata/skipped_to_failing.txtar
index 98935e8..55c12a8 100644
--- a/claudetool/testdata/skipped_to_failing.txtar
+++ b/claudetool/testdata/skipped_to_failing.txtar
@@ -27,7 +27,7 @@
 -- .run_test --
 # Errors
 
-Test regressions detected between initial commit (3635353dfefb2fa652728318567209ccfc4aba42) and HEAD:
+Test regressions detected between initial commit (INITIAL_COMMIT_HASH) and HEAD:
 
 1: sketch.dev.TestP: Was skipped, now failing
 
diff --git a/claudetool/testdata/vet_error_test.txtar b/claudetool/testdata/vet_error_test.txtar
index 0163a81..6f2c7c7 100644
--- a/claudetool/testdata/vet_error_test.txtar
+++ b/claudetool/testdata/vet_error_test.txtar
@@ -23,7 +23,7 @@
 -- .run_test --
 # Errors
 
-Test regressions detected between initial commit (656e4d573cb77a30ebce29ebb974533ece282946) and HEAD:
+Test regressions detected between initial commit (INITIAL_COMMIT_HASH) and HEAD:
 
 1: sketch.dev: Previously had no tests, now has build/vet errors