diff-local always fails with "mprcontents directory not found" on a project where the directory exists

[TOFBuck]

diff-local always fails with "mprcontents directory not found" — on a project where the directory exists and mxcli itself stats it successfully

mxcli version

mxcli version v0.20.0 (2026-08-28T13:22:53Z)

Also reproduced on v0.19.0 and v0.18.0 (same binary family, same machine).
This is not a v0.20.0 regression — the command appears to have never worked here.

Mendix version

10.24.24.119653 (MPR v2 format, mprcontents/ on disk — confirmed by mxcli's
own connect log: "mpr_format":2)

Environment

• linux / arm64, Go 1.26.6 (from mxcli's session log)
• Project is at the git repository root, .git is a normal directory
• mprcontents/ is tracked by git

Severity

Medium.

diff-local is the only command that answers "what changed in the model since a git
ref". It is the documented way to derive a change list before handing model work to
another branch. With it broken there is no substitute: mxcli diff compares an MDL
script against the project, which is a different question.

Not High, because it is a read-only reporting command — no data or security impact.

Steps to reproduce

On any MPR v2 project inside a git repository, with mprcontents/ tracked:

mxcli diff-local -p App.mpr

Expected behaviour

Either a diff of the changed .mxunit files, or "no local changes".

Actual behaviour

Connected to: App.mpr (Mendix 10.24.24.119653)
Error: mprcontents directory not found

The connect step succeeds and correctly reports mpr_format: 2, which already proves
mxcli located mprcontents/.

Evidence: mxcli finds the directory and then reports it missing

strace on the failing run (strace -f -e trace=openat,newfstatat,statx,execve):

newfstatat(AT_FDCWD, "App.mpr",     {st_mode=S_IFREG|0644, st_size=413696, ...}, 0) = 0
newfstatat(AT_FDCWD, "mprcontents", {st_mode=S_IFDIR|0755, st_size=8288,   ...}, 0) = 0
                                     ^^^^^^^^^ is a directory              ^^^ success
...
Error: mprcontents directory not found

Two further observations from the same trace:

1. mprcontents is stat'ed exactly once, during connect, and it succeeds. The
   diff-local code path never stats it again — so whatever it tests, it is not the
   filesystem.
2. .git is never opened and git is never exec'ed. The trace contains exactly
   one execve (mxcli itself) and zero accesses to any .git path. The command's own
   embedded documentation says it works by running git diff --name-status, so it
   aborts before reaching any of its actual work.

Directory state at the time of the run:

$ ls -ld mprcontents
drwxr-xr-x 259 user user 8288 mprcontents

$ ls mprcontents | wc -l
257

$ git ls-tree HEAD --name-only | grep -x mprcontents
mprcontents

The failure is invariant

Every one of these produces the identical message:

Variation	Result
-p App.mpr	fail
-p ./App.mpr	fail
-p /abs/path/App.mpr	fail
run from the parent directory, -p subdir/App.mpr	fail
--ref HEAD (default)	fail
--ref HEAD~1	fail
--ref origin/<branch>	fail
--format struct / --format unified	fail
--json	fail, same plain-text message (not JSON-wrapped)
working tree clean	fail
working tree with modified .mxunit files	fail
mxcli v0.20.0 / v0.19.0 / v0.18.0	fail all three

Notes for triage

• There appear to be two distinct "no mprcontents" strings in the binary:
  Not an MPR v2 project (no mprcontents directory) and
  mprcontents directory not found. Only the second one is emitted here, and it is
  emitted after the v2 detection has already succeeded.
• Because --json does not wrap this error, an automated caller cannot distinguish it
  from any other failure.

Workaround

None for this command. The nearest substitute answers a different question:

mxcli diff -p App.mpr script.mdl --format struct    # script vs project, not model vs git

Diagnostic bundle

Yes — mxcli-diag-20260904-091156.tar.gz, available on request.

[TOFBuck]

Additional evidence from an earlier, independent reproduction of this same defect.

It was first hit on mxcli v0.18.0 (2026-08-14T20:29:13Z), on the same MPR v2 /
Mendix 10.24.24.119653 project, and written up at the time but never filed. That makes
the earliest confirmed occurrence 2026-08-19, three releases before the version in the
report above.

Control: every other command works, same project, same shell, same cwd

This is the part the original report did not include. In the same session in which
diff-local failed, with mprcontents/ untouched:

$ mxcli diff -p App.mpr mdlsource/some-script.mdl --format struct
Connected to: App.mpr (Mendix 10.24.24.119653)
... Summary: 2 new, 4 modified, 1 unchanged        # works

$ mxcli lint -p App.mpr
... 1866 issues: 0 errors, 491 warnings, 1375 info # works

$ mxcli describe -p App.mpr entity SomeModule.SomeEntity
... # works

So the project opens, the model loads, and the catalog is readable. Only diff-local
claims the directory is missing.

At that time the working tree also had modified .mxunit files that git status
listed normally — i.e. there was real work for the command to report, and it still
failed.

Possibly related, in case the comparison code is shared

On the same project, mxcli diff -p App.mpr <script> --format struct reported two of
three already-existing associations as + New, and the third as (no changes). All
three had been created by an earlier exec of that same script, and
SHOW ASSOCIATIONS confirmed all three existed.

Not investigated further, and possibly unrelated — raised only because it is the other
place in mxcli where model state is compared against something, and it was wrong in the
same session.

A second diagnostic bundle from that earlier run is available on request:
mxcli-diag-20260819-094451.tar.gz.