I solved the following tutorial problem on JuMP’s documentation page, but the result and summary file are not generated (I do set the `result`

and `summary`

parameters to 1):

```
using JuMP, BARON
rocket = Model(BARON.Optimizer)
set_optimizer_attribute(rocket, "MaxTime", 500)
set_optimizer_attribute(rocket, "NumLoc", 1)
set_optimizer_attribute(rocket, "results", 1)
set_optimizer_attribute(rocket, "summary", 1)
h_0 = 1 # Initial height
v_0 = 0 # Initial velocity
m_0 = 1 # Initial mass
g_0 = 1 # Gravity at the surface
T_c = 3.5 # Used for thrust
h_c = 500 # Used for drag
v_c = 620 # Used for drag
m_c = 0.6 # Fraction of initial mass left at end
c = 0.5 * sqrt(g_0 * h_0) # Thrust-to-fuel mass
m_f = m_c * m_0 # Final mass
D_c = 0.5 * v_c * m_0 / g_0 # Drag scaling
T_max = T_c * g_0 * m_0 # Maximum thrust
n = 800 # Time steps
@variables(rocket, begin
Δt ≥ 0, (start = 1 / n) # Time step
# State variables
v[1:n] ≥ 0 # Velocity
h[1:n] ≥ h_0 # Height
m_f ≤ m[1:n] ≤ m_0 # Mass
# Control variables
0 ≤ T[1:n] ≤ T_max # Thrust
end);
@objective(rocket, Max, h[n])
fix(v[1], v_0; force = true)
fix(h[1], h_0; force = true)
fix(m[1], m_0; force = true)
fix(m[n], m_f; force = true)
@NLexpressions(
rocket,
begin
# Drag(h,v) = Dc v^2 exp( -hc * (h - h0) / h0 )
drag[j = 1:n], D_c * (v[j]^2) * exp(-h_c * (h[j] - h_0) / h_0)
# Grav(h) = go * (h0 / h)^2
grav[j = 1:n], g_0 * (h_0 / h[j])^2
# Time of flight
t_f, Δt * n
end
);
for j in 2:n
# h' = v
# Rectangular integration
# @NLconstraint(rocket, h[j] == h[j - 1] + Δt * v[j - 1])
# Trapezoidal integration
@NLconstraint(rocket, h[j] == h[j-1] + 0.5 * Δt * (v[j] + v[j-1]))
# v' = (T-D(h,v))/m - g(h)
# Rectangular integration
# @NLconstraint(
# rocket,
# v[j] == v[j - 1] + Δt *((T[j - 1] - drag[j - 1]) / m[j - 1] - grav[j - 1])
# )
# Trapezoidal integration
@NLconstraint(
rocket,
v[j] ==
v[j-1] +
0.5 *
Δt *
(
(T[j] - drag[j] - m[j] * grav[j]) / m[j] +
(T[j-1] - drag[j-1] - m[j-1] * grav[j-1]) / m[j-1]
)
)
# m' = -T/c
# Rectangular integration
# @NLconstraint(rocket, m[j] == m[j - 1] - Δt * T[j - 1] / c)
# Trapezoidal integration
@NLconstraint(rocket, m[j] == m[j-1] - 0.5 * Δt * (T[j] + T[j-1]) / c)
end
optimize!(rocket)
```

I am using Julia 1.8.2, BARON v0.8.0, and JuMP v1.4.0.

Any help or pointers on what exactly is going wrong here would be appreciated. Thanks!