Bug#1143352: ocaml-crunch: FTBFS: dh_auto_test: error: dune runtest -j 2 -p crunch returned exit code 1

Package: src:ocaml-crunch
Version: 4.0.0-1
Severity: serious
Tags: ftbfs forky sid

Dear maintainer:

During a rebuild of all packages in unstable, this package failed to build.

Below you will find the last part of the build log (probably the most
relevant part, but not necessarily). If required, the full build log
is available here:

https://people.debian.org/~sanvila/build-logs/202608/

About the archive rebuild: The build was made on virtual machines from AWS,
using sbuild and a reduced chroot with only build-essential packages.

If you cannot reproduce the bug please contact me privately, as I
am willing to provide ssh access to a virtual machine where the bug is
fully reproducible.

If this is really a bug in one of the build-depends, please use
reassign and add an affects on src:ocaml-crunch, so that this is still
visible in the BTS web page for this package.

Thanks.

--------------------------------------------------------------------------------
[...]
 debian/rules clean
dh clean --with ocaml --buildsystem ocaml_dune
   dh_auto_clean -O--buildsystem=ocaml_dune
	dune clean
   dh_autoreconf_clean -O--buildsystem=ocaml_dune
   dh_ocamlclean -O--buildsystem=ocaml_dune
   dh_clean -O--buildsystem=ocaml_dune
 debian/rules binary
dh binary --with ocaml --buildsystem ocaml_dune
   dh_update_autotools_config -O--buildsystem=ocaml_dune
   dh_autoreconf -O--buildsystem=ocaml_dune
   dh_ocamlinit -O--buildsystem=ocaml_dune
   dh_auto_configure -O--buildsystem=ocaml_dune
   dh_auto_build -O--buildsystem=ocaml_dune
	dune build -j 2 -p crunch
   dh_auto_test -O--buildsystem=ocaml_dune
	dune runtest -j 2 -p crunch
(cd _build/default/test && ../src/main.exe --mode=lwt -o t1.ml t1)
Generating t1.ml
Generating t1.mli
(cd _build/default/test && ../src/main.exe --mode=plain -o t1_plain.ml t1)
Generating t1_plain.ml
Skipping generation of .mli
(cd _build/default/test && ../src/main.exe --mode=plain -e ext -o t1_plain_ext.ml t1)
Generating t1_plain_ext.ml
Skipping generation of .mli
File "test/t1.expected.ml", line 1, characters 0-0:
(cd _build/default && /usr/bin/diff -u --label test/t1.expected.ml --label test/t1.ml test/t1.expected.ml test/t1.ml)
--- test/t1.expected.ml
+++ test/t1.ml
@@ -1,4 +1,4 @@
-(* Generated by: ocaml-crunch
+(* Generated by: main
    Creation date: Thu, 1 Jan 1970 00:00:00 GMT *)
 
 module Internal = struct
File "test/t1.expected.mli", line 1, characters 0-0:
(cd _build/default && /usr/bin/diff -u --label test/t1.expected.mli --label test/t1.mli test/t1.expected.mli test/t1.mli)
--- test/t1.expected.mli
+++ test/t1.mli
@@ -1,4 +1,4 @@
-(* Generated by: ocaml-crunch
+(* Generated by: main
    Creation date: Thu, 1 Jan 1970 00:00:00 GMT *)
 
 include Mirage_kv.RO
File "test/t1_plain.expected.ml", line 1, characters 0-0:
(cd _build/default && /usr/bin/diff -u --label test/t1_plain.expected.ml --label test/t1_plain.ml test/t1_plain.expected.ml test/t1_plain.ml)
--- test/t1_plain.expected.ml
+++ test/t1_plain.ml
@@ -1,4 +1,4 @@
-(* Generated by: ocaml-crunch
+(* Generated by: main
    Creation date: Thu, 1 Jan 1970 00:00:00 GMT *)
 
 module Internal = struct
File "test/t1_plain_ext.expected.ml", line 1, characters 0-0:
(cd _build/default && /usr/bin/diff -u --label test/t1_plain_ext.expected.ml --label test/t1_plain_ext.ml test/t1_plain_ext.expected.ml test/t1_plain_ext.ml)
--- test/t1_plain_ext.expected.ml
+++ test/t1_plain_ext.ml
@@ -1,4 +1,4 @@
-(* Generated by: ocaml-crunch
+(* Generated by: main
    Creation date: Thu, 1 Jan 1970 00:00:00 GMT *)
 
 module Internal = struct
(cd _build/default/test && ./consumer.exe)
read a.ext successfully
read 'c' successfully
read 'd' successfully
read e/f successfully
dh_auto_test: error: dune runtest -j 2 -p crunch returned exit code 1
make: *** [debian/rules:7: binary] Error 25
dpkg-buildpackage: error: debian/rules binary subprocess failed with exit status 2
--------------------------------------------------------------------------------