Crash when targetting a vessel

[msabathier]

Hi,
I just updated Principia to the latest version and then tried to finish my Mun mission by doing a rendez-vous between the lander and the orbiter but as soon as i click on the vessel to target it, i get a freeze (about 3-4 seconds) and then KSP just closes without any messages.
I tried both targetting the lander with the orbiter as the active vessel and targetting the orbiter with the lander as the active vessel but i get the freeze and crash each time.

I turned journaling on and reproduced the issue here are the logs :
INFO.20230520-102545.9324.log
WARNING.20230520-102545.9324.log
ERROR.20230520-102545.9324.log
FATAL.20230520-103014.9324.log

and the journal : JOURNAL.20230520-102851

I have a good amount of mods on this install, let me know if you need the list.

Also, since i am a bit of an idiot, i did not make a backup of the penultimate principia release binaries... Is there a place where i can find the binaries for Ὑπατία ? Or do i need to build it from the source ?

Thanks in advance for your time and response

[jd284]

I have the same crash (I think), when switching to the TgtEO frame on a ship that already has the target set. It's probably not the targeting itself, but the automatic switch to TgtEO.

[pleroy]

Look at the history of the README.md file, you'll find the links to the previous versions.

[eggrobin]

Decoded stack trace:

Principia/ksp_plugin/interface_planetarium.cpp

Lines 171 to 180 in 9f3105e

	int* const vertex_count) {
	journal::Method<journal::PlanetariumPlotPrediction> m(
	{planetarium, plugin, vessel_guid, vertices, vertices_size},
	{vertex_count});
	CHECK_NOTNULL(plugin);
	CHECK_NOTNULL(planetarium);
	*vertex_count = 0;
	auto const prediction = plugin->GetVessel(vessel_guid)->prediction();
	planetarium->PlotMethod3(

Principia/ksp_plugin/planetarium.cpp

Lines 279 to 286 in 9f3105e

	int max_points) const {
	if (begin == end) {
	return;
	}
	auto last = std::prev(end);
	auto const begin_time = std::max(begin->time, plotting_frame_->t_min());
	auto const last_time = std::min(last->time, plotting_frame_->t_max());
	PlotMethod3(

Principia/ksp_plugin/planetarium.cpp

Lines 298 to 351 in 9f3105e

	Length* const minimal_distance) const {
	double const tan²_angular_resolution =
	Pow<2>(parameters_.tan_angular_resolution_);
	auto const final_time = reverse ? first_time : last_time;
	auto previous_time = reverse ? last_time : first_time;
	if (minimal_distance != nullptr) {
	*minimal_distance = Infinity<Length>;
	}
	Sign const direction = reverse ? Sign::Negative() : Sign::Positive();
	if (direction * (final_time - previous_time) <= Time{}) {
	return;
	}
	SimilarMotion<Barycentric, Navigation> to_plotting_frame_at_t =
	plotting_frame_->ToThisFrameAtTimeSimilarly(previous_time);
	DegreesOfFreedom<Navigation> const initial_degrees_of_freedom =
	to_plotting_frame_at_t(
	trajectory.EvaluateDegreesOfFreedom(previous_time));
	Position<Navigation> previous_position =
	initial_degrees_of_freedom.position();
	Velocity<Navigation> previous_velocity =
	initial_degrees_of_freedom.velocity();
	Time Δt = final_time - previous_time;
	add_point(plotting_to_scaled_space_(previous_position));
	int points_added = 1;
	Instant t;
	double estimated_tan²_error;
	std::optional<DegreesOfFreedom<Barycentric>>
	degrees_of_freedom_in_barycentric;
	Position<Navigation> position;
	Square<Length> minimal_squared_distance = Infinity<Square<Length>>;
	goto estimate_tan²_error;
	while (points_added < max_points &&
	direction * (previous_time - final_time) < Time{}) {
	do {
	// One square root because we have squared errors, another one because the
	// errors are quadratic in time (in other words, two square roots because
	// the squared errors are quartic in time).
	// A safety factor prevents catastrophic retries.
	Δt *= 0.9 * Sqrt(Sqrt(tan²_angular_resolution / estimated_tan²_error));
	estimate_tan²_error:
	t = previous_time + Δt;
	if (direction * (t - final_time) > Time{}) {
	t = final_time;
	Δt = t - previous_time;
	}
	Position<Navigation> const extrapolated_position =
	previous_position + previous_velocity * Δt;
	to_plotting_frame_at_t = plotting_frame_->ToThisFrameAtTimeSimilarly(t);

Principia/physics/rigid_reference_frame_body.hpp

Lines 31 to 32 in 9f3105e

	Instant const& t) const {
	return ToThisFrameAtTime(t).template Forget<SimilarMotion>();

Principia/physics/body_centred_body_direction_reference_frame_body.hpp

Lines 103 to 104 in 9f3105e

	ToThisFrameAtTime(Instant const& t) const {
	DegreesOfFreedom<InertialFrame> const primary_degrees_of_freedom =

Principia/physics/discrete_trajectory_segment_body.hpp

Lines 160 to 166 in 9f3105e

	Instant const& t) const {
	auto const it = timeline_.lower_bound(t);
	if (it->time == t) {
	return it->degrees_of_freedom;
	}
	CHECK_LT(t_min(), t);
	CHECK_GT(t_max(), t);

[pleroy]

We'll publish an updated ابن الهيثم release in a few hours.

[pleroy]

@msabathier Thanks for the report, and for providing logs and a journal, it was very helpful.

[msabathier]

Well thank you @pleroy and @eggrobin for the speedy support !