I installed all your packages, and I have MiniZinc v0.3.11:
(tmp) pkg> st
Status `~/repos/tmp/Project.toml`
[07493b3f] Alpine v0.5.6
[7c4d4715] AmplNLWriter v1.2.1
[6f275bd8] BLISBLAS v0.1.1
[227a2e2d] COPT v1.1.18
[bb8be931] EAGO v0.8.1
[7a1cc6ca] FFTW v1.8.0
[87dc4568] HiGHS v1.9.1
⌅ [d1acc4aa] IntervalArithmetic v0.20.9
[b6b21f68] Ipopt v1.6.4
[4076af6c] JuMP v1.22.2
[2ddba703] Juniper v0.9.2
[19f71287] MAiNGO v0.2.2
[33e6dc65] MKL v0.7.0
[a7f392d2] MiniZinc v0.3.11
⌃ [82193955] SCIP v0.11.6
[29cba6d7] Bonmin_jll v100.800.901+0
[f09e9e23] Couenne_jll v0.500.801+0
[9cc047cb] Ipopt_jll v300.1400.1600+0
[17f450c3] LAPACK32_jll v3.12.0+0
[c1ab834c] SHOT_jll v100.100.0+0
[319450e9] SPRAL_jll v2024.5.8+0
[e47b3055] blis32_jll v1.0.0+0
Info Packages marked with ⌃ and ⌅ have new versions available. Those with ⌃ may be upgradable, but those with ⌅ are restricted by compatibility constraints from upgrading. To see why use `status --outdated`
(tmp) pkg>
OK, I am on Linux.
What is the output if you try:
pkg> up
Or, if that does not help, try:
pkg> add MiniZinc#v0.3.11
?