Thanks for the explaination, Bo. In this case the actual autopkgtests failure is still caused by https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1073595
Attached the log for reference: autopkgtest [09:19:30]: test helloworld: [----------------------- Warning: Cache directories could not be created: Permission denied; disabling cache Hint: Make sure the directory /home/vscode/.cache/dune/db/temp can be created File "dune", line 2, characters 7-18: 2 | (name hello_world) ^^^^^^^^^^^ /usr/bin/ld: /usr/lib/x86_64-linux-gnu/ocaml/5.3.0/luv/c/libluv_c_stubs.a(c_generated_functions.o): in function `luv_stub_266_uv_wtf8_length_as_utf16': (.text+0x2c3d): undefined reference to `uv_wtf8_length_as_utf16' /usr/bin/ld: /usr/lib/x86_64-linux-gnu/ocaml/5.3.0/luv/c/libluv_c_stubs.a(c_generated_functions.o): in function `luv_stub_267_uv_wtf8_to_utf16': (.text+0x2c69): undefined reference to `uv_wtf8_to_utf16' /usr/bin/ld: /usr/lib/x86_64-linux-gnu/ocaml/5.3.0/luv/c/libluv_c_stubs.a(helpers.o): in function `luv_utf16_length_as_wtf8': (.text+0xce1): undefined reference to `uv_utf16_length_as_wtf8' /usr/bin/ld: /usr/lib/x86_64-linux-gnu/ocaml/5.3.0/luv/c/libluv_c_stubs.a(helpers.o): in function `luv_utf16_to_wtf8': (.text+0xcf1): undefined reference to `uv_utf16_to_wtf8' collect2: error: ld returned 1 exit status File "caml_startup", line 1: Error: Error during linking (exit code 1) autopkgtest [09:19:31]: test helloworld: -----------------------] autopkgtest [09:19:31]: test helloworld: - - - - - - - - - - results - - - - - - - - - - helloworld FAIL non-zero exit status 1 autopkgtest [09:19:31]: test helloworld: - - - - - - - - - - stderr - - - - - - - - - - Warning: Cache directories could not be created: Permission denied; disabling cache Hint: Make sure the directory /home/vscode/.cache/dune/db/temp can be created File "dune", line 2, characters 7-18: 2 | (name hello_world) ^^^^^^^^^^^ /usr/bin/ld: /usr/lib/x86_64-linux-gnu/ocaml/5.3.0/luv/c/libluv_c_stubs.a(c_generated_functions.o): in function `luv_stub_266_uv_wtf8_length_as_utf16': (.text+0x2c3d): undefined reference to `uv_wtf8_length_as_utf16' /usr/bin/ld: /usr/lib/x86_64-linux-gnu/ocaml/5.3.0/luv/c/libluv_c_stubs.a(c_generated_functions.o): in function `luv_stub_267_uv_wtf8_to_utf16': (.text+0x2c69): undefined reference to `uv_wtf8_to_utf16' /usr/bin/ld: /usr/lib/x86_64-linux-gnu/ocaml/5.3.0/luv/c/libluv_c_stubs.a(helpers.o): in function `luv_utf16_length_as_wtf8': (.text+0xce1): undefined reference to `uv_utf16_length_as_wtf8' /usr/bin/ld: /usr/lib/x86_64-linux-gnu/ocaml/5.3.0/luv/c/libluv_c_stubs.a(helpers.o): in function `luv_utf16_to_wtf8': (.text+0xcf1): undefined reference to `uv_utf16_to_wtf8' collect2: error: ld returned 1 exit status File "caml_startup", line 1: Error: Error during linking (exit code 1) autopkgtest [09:19:31]: @@@@@@@@@@@@@@@@@@@@ summary helloworld FAIL non-zero exit status 1 E: Autopkgtest run failed. Best, Andy