Cannot build with opam

[nathanfarlow]

After installing obytelib with the symlink trick opam install ocamlclean fails with the following output:

The following actions will be performed:
  ∗ install ocamlclean 2.3

<><> Processing actions <><><><><><><><><><><><><><><><><><><><><><><><><><><><>
⬇ retrieved ocamlclean.2.3  (cached)
[ERROR] The compilation of ocamlclean.2.3 failed at "make".

#=== ERROR while compiling ocamlclean.2.3 =====================================#
# context     2.1.2 | linux/x86_64 | ocaml.4.13.1 | https://opam.ocaml.org#92063b79
# path        ~/.opam/default/.opam-switch/build/ocamlclean.2.3
# command     ~/.opam/opam-init/hooks/sandbox.sh build make
# exit-code   2
# env-file    ~/.opam/log/ocamlclean-45324-089783.env
# output-file ~/.opam/log/ocamlclean-45324-089783.out
### output ###
# Hint: Recursive traversal of subdirectories was not enabled for this build,
# [...]
#   you should add the option "-r" or create an empty '_tags' file.
#   
#   To enable recursive traversal for some subdirectories only, you can use the
#   following '_tags' file:
#   
#       true: -traverse
#       <dir1> or <dir2>: traverse
#       
# make[1]: *** [Makefile:24: _build/main.native] Error 10
# make[1]: Leaving directory '/home/nathan/.opam/default/.opam-switch/build/ocamlclean.2.3/src'
# make: *** [Makefile:15: all] Error 2



<><> Error report <><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><>
┌─ The following actions failed
│ λ build ocamlclean 2.3
└─ 

where ~/.opam/log/ocamlclean-45324-089783.out is

make[1]: Entering directory '/home/nathan/.opam/default/.opam-switch/build/ocamlclean.2.3/src'
cp /home/nathan/.opam/default/.opam-switch/build/ocamlclean.2.3/etc/config.ml config.ml
/usr/lib/ocaml/../../bin/ocamlbuild -cflags -w,@a-4-70,-warn-error,A,-safe-string,-strict-formats,-strict-sequence -lflags -w,@a-4-70,-warn-error,A,-safe-string,-strict-formats,-strict-sequence -no-links -classic-display -cflags -I,+../obytelib,-g -lflags -I,+../obytelib,obytelib.cmxa main.native
ocamldep.opt -modules main.ml > main.ml.depends
ocamldep.opt -modules cleanbra.ml > cleanbra.ml.depends
ocamldep.opt -modules step1.ml > step1.ml.depends
ocamlc.opt -c -w @a-4-70 -warn-error A -safe-string -strict-formats -strict-sequence -I +../obytelib -g -o step1.cmo step1.ml
+ ocamlc.opt -c -w @a-4-70 -warn-error A -safe-string -strict-formats -strict-sequence -I +../obytelib -g -o step1.cmo step1.ml
File "step1.ml", line 12, characters 5-30:
12 | open OByteLib.Normalised_instr
          ^^^^^^^^^^^^^^^^^^^^^^^^^
Error: Unbound module OByteLib
Command exited with code 2.
Hint: Recursive traversal of subdirectories was not enabled for this build,
  as the working directory does not look like an ocamlbuild project (no
  '_tags' or 'myocamlbuild.ml' file). If you have modules in subdirectories,
  you should add the option "-r" or create an empty '_tags' file.
  
  To enable recursive traversal for some subdirectories only, you can use the
  following '_tags' file:
  
      true: -traverse
      <dir1> or <dir2>: traverse
      
make[1]: *** [Makefile:24: _build/main.native] Error 10
make[1]: Leaving directory '/home/nathan/.opam/default/.opam-switch/build/ocamlclean.2.3/src'
make: *** [Makefile:15: all] Error 2

Note that

nathan@laptop:~$ opam install obytelib
[NOTE] Package obytelib is already installed (current version is 1.6).