diff -r fc6d8a2895ca -r ef03cc736d31 src/Pure/Tools/build_process.scala
--- a/src/Pure/Tools/build_process.scala	Thu Aug 10 12:15:40 2023 +0200
+++ b/src/Pure/Tools/build_process.scala	Thu Aug 10 12:26:20 2023 +0200
@@ -121,8 +121,8 @@
               val sources_shasum0 = session0.sources_shasum
 
               def err(msg: String, a: String, b: String): Nothing =
-                error("Conflicting dependencies for session " + quote(name) + ": " +
-                  msg + "\n" + a + "\nvs.\n" + b)
+                error("Conflicting dependencies for session " + quote(name) + ": " + msg + "\n" +
+                  Library.indent_lines(2, a) + "\nvs.\n" + Library.indent_lines(2, b))
 
               if (prefs0 != prefs) {
                 err("preferences disagree",
@@ -134,7 +134,9 @@
               if (sources_shasum0 != sources_shasum) {
                 val a = sources_shasum0 - sources_shasum
                 val b = sources_shasum - sources_shasum0
-                err("sources disagree", a.toString, b.toString)
+                err("sources disagree",
+                  Library.trim_line(a.toString),
+                  Library.trim_line(b.toString))
               }
 
               graph0