Compilation fails on macOS

[turbolent]

I tried compiling jackline on macOS by installing OCaml and following the instructions:

opam install jackline

The following actions will be performed:
  ∗ install erm_xml  0.3.1 [required by erm_xmpp]
  ∗ install erm_xmpp 0.3   [required by jackline]
  ∗ install jackline 0.1.0
===== ∗ 3 =====
Do you want to continue? [Y/n] y

<><> Gathering sources ><><><><><><><><><><><><><><><><><><><><><><><><><><>  🐫 
[jackline.0.1.0] synchronised from git+https://github.com/hannesm/jackline.git
[erm_xml.0.3.1] synchronised from git+https://github.com/hannesm/xml.git
[erm_xmpp.0.3] synchronised from git+https://github.com/hannesm/xmpp.git#otr

<><> Processing actions <><><><><><><><><><><><><><><><><><><><><><><><><><>  🐫 
[ERROR] The compilation of erm_xml failed at "/Users/bastian/.opam/opam-init/hooks/sandbox.sh build ocaml setup.ml -install".

#=== ERROR while compiling erm_xml.0.3.1 ======================================#
# context     2.0.0 | macos/x86_64 | ocaml-system.4.07.0 | git+https://github.com/hannesm/xmpp-opam.git
# path        ~/.opam/default/.opam-switch/build/erm_xml.0.3.1
# command     ~/.opam/opam-init/hooks/sandbox.sh build ocaml setup.ml -install
# exit-code   1
# env-file    ~/.opam/log/erm_xml-27315-487c34.env
# output-file ~/.opam/log/erm_xml-27315-487c34.out
### output ###
# ocamlfind: /Users/bastian/.opam/default/lib/erm_xml/xml.mli: Operation not permitted
# E: Failure("Command ''/Users/bastian/.opam/default/bin/ocamlfind' install erm_xml src/META _build/src/xml.cmx _build/src/xmllexer_generic.cmx _build/src/xmllexer.cmx _build/src/xmllexerI.cmx _build/src/xmllexerI2.cmx _build/src/xmllexerE.cmx _build/src/light_xml.cmx _build/src/xml_encode.cmx _build/src/xml_decode.cmx _build/src/xml.annot _build/src/xml.cmt _build/src/xml.cmti _build/src/xml.c[...]

<><> Error report <><><><><><><><><><><><><><><><><><><><><><><><><><><><><>  🐫 
┌─ The following actions failed
│ λ build erm_xml 0.3.1
└─ 
╶─ No changes have been performed

[hannesm]

would you mind to test this with, instead of xmpp-opam, using https://github.com/hannesm/jackline-opam ? this repository is opam2 only, but has sandboxing features for erm_xml and erm_xmpp. You can even verify the signatures (in case you trust my root key).

[schoeke]

I encountered the same problem just now. I "solved" it by deleting ~/.opam and reinitializing it. After that it went smoothly.