interrupting devtools::test() leaves behind recursively-faulting R processes

[kevinushey]

To reproduce, in RStudio:

• Use Cmd + Shift + T to run tests,
• Wait until the parallel test runner has started,
• Stop the running tests with the stop button.

The running R process receives a SIGTERM and exits, but the sub-processes are left behind.

At least on macOS, those processes get stuck in an infinite busy loop, chewing up lots of CPU. lldb reports:

(lldb) bt
* thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0x7)
  * frame #0: 0x00000001026a74fc libR.dylib`R_GetTracebackOnly(skip=0) at errors.c:1564:19 [opt]
    frame #1: 0x00000001026a76a4 libR.dylib`R_GetTraceback(skip=<unavailable>) at errors.c:1605:9 [opt]
    frame #2: 0x0000000102701720 libR.dylib`sigactionSegv(signum=11, ip=0x00000001284a8250, context=<unavailable>) at main.c:602:2 [opt]
    frame #3: 0x0000000186206a24 libsystem_platform.dylib`_sigtramp + 56

so it seems like the R processes are getting stuck recursively handling SIGSEGV errors.

[kevinushey]

One workaround is to set:

Sys.setenv(R_NO_SEGV_HANDLER = 1)

so that R doesn't try to install its SEGV handlers.

[kevinushey]

I filed a bug report for R as well; I believe R should be unsetting the SEGV handler while processing the signal. https://bugs.r-project.org/show_bug.cgi?id=18551

[gaborcsardi]

Seems like R_NO_SEGV_HANDLER needs R 4.1.2, but hopefully we can find a solution that works on older R as well.

[gaborcsardi]

Btw. I also don't really understand why the subprocesses of the test process get SEGV signals.

[kevinushey]

Here's a traceback I was able to capture:

Thread 0::  Dispatch queue: com.apple.main-thread
0   libsystem_pthread.dylib       	       0x1861d3788 pthread_self + 24
1   processx.so                   	       0x104d71274 processx__sigchld_callback + 52
2   libsystem_platform.dylib      	       0x186206a24 _sigtramp + 56
3   libR.dylib                    	       0x100ac8f0c R_restore_globals + 24 (context.c:178) [inlined]
4   libR.dylib                    	       0x100ac8f0c R_jumpctxt + 268 (context.c:231)
5   libR.dylib                    	       0x100ac9348 Rf_endcontext + 520 (context.c:321)
6   libR.dylib                    	       0x100b2bd24 R_execClosure + 3108 (eval.c:2190)
7   libR.dylib                    	       0x100b2a58c Rf_applyClosure + 524 (eval.c:2113)
8   libR.dylib                    	       0x100b16244 bcEval + 27460 (eval.c:7414)
9   libR.dylib                    	       0x100b0f088 Rf_eval + 584 (eval.c:1013)
10  libR.dylib                    	       0x100b2bd0c R_execClosure + 3084
11  libR.dylib                    	       0x100b2a58c Rf_applyClosure + 524 (eval.c:2113)
12  libR.dylib                    	       0x100b0f35c Rf_eval + 1308 (eval.c:1140)
13  libR.dylib                    	       0x100b077cc vsignalError + 1100 (errors.c:1903)
14  libR.dylib                    	       0x100b07330 Rf_errorcall + 176 (errors.c:912)
15  libR.dylib                    	       0x100b08a70 Rf_error + 112 (errors.c:963)
16  libR.dylib                    	       0x100b6d25c SET_STRING_ELT + 412 (memory.c:4088)
17  libR.dylib                    	       0x100ad81a0 writeline + 56 (deparse.c:1528) [inlined]
18  libR.dylib                    	       0x100ad81a0 deparse2 + 80 (deparse.c:554) [inlined]
19  libR.dylib                    	       0x100ad81a0 deparse1WithCutoff + 544 (deparse.c:282)
20  libR.dylib                    	       0x100ad8438 Rf_deparse1m + 120 (deparse.c:198)
21  libR.dylib                    	       0x100b0a834 R_GetTraceback + 308 (errors.c:1613)
22  libR.dylib                    	       0x100b65f60 sigactionSegv + 352 (main.c:602)
23  libsystem_platform.dylib      	       0x186206a24 _sigtramp + 56
24  libR.dylib                    	       0x100ac8f0c R_restore_globals + 24 (context.c:178) [inlined]
25  libR.dylib                    	       0x100ac8f0c R_jumpctxt + 268 (context.c:231)
26  libR.dylib                    	       0x100ac9348 Rf_endcontext + 520 (context.c:321)
27  libR.dylib                    	       0x100b2bd24 R_execClosure + 3108 (eval.c:2190)
28  libR.dylib                    	       0x100b2a58c Rf_applyClosure + 524 (eval.c:2113)
29  libR.dylib                    	       0x100b16244 bcEval + 27460 (eval.c:7414)
30  libR.dylib                    	       0x100b0f088 Rf_eval + 584 (eval.c:1013)
31  libR.dylib                    	       0x100b2bd0c R_execClosure + 3084
32  libR.dylib                    	       0x100b2a58c Rf_applyClosure + 524 (eval.c:2113)
33  libR.dylib                    	       0x100b0f35c Rf_eval + 1308 (eval.c:1140)
34  libR.dylib                    	       0x100b2fe34 do_eval + 1396 (eval.c:3625)
35  libR.dylib                    	       0x100b16a64 bcEval + 29540 (eval.c:7446)
36  libR.dylib                    	       0x100b0f088 Rf_eval + 584 (eval.c:1013)
37  libR.dylib                    	       0x100b2bd0c R_execClosure + 3084
38  libR.dylib                    	       0x100b2a58c Rf_applyClosure + 524 (eval.c:2113)
39  libR.dylib                    	       0x100b16244 bcEval + 27460 (eval.c:7414)
40  libR.dylib                    	       0x100b0f088 Rf_eval + 584 (eval.c:1013)
41  libR.dylib                    	       0x100b2bd0c R_execClosure + 3084
42  libR.dylib                    	       0x100b2a58c Rf_applyClosure + 524 (eval.c:2113)
43  libR.dylib                    	       0x100b0f35c Rf_eval + 1308 (eval.c:1140)
44  libR.dylib                    	       0x100b30098 do_eval + 2008 (eval.c:3648)
45  libR.dylib                    	       0x100b16a64 bcEval + 29540 (eval.c:7446)
46  libR.dylib                    	       0x100b0f088 Rf_eval + 584 (eval.c:1013)
47  libR.dylib                    	       0x100b2bd0c R_execClosure + 3084
48  libR.dylib                    	       0x100b2a58c Rf_applyClosure + 524 (eval.c:2113)
49  libR.dylib                    	       0x100b16244 bcEval + 27460 (eval.c:7414)
50  libR.dylib                    	       0x100b0f088 Rf_eval + 584 (eval.c:1013)
51  libR.dylib                    	       0x100b29ca4 forcePromise + 164 (eval.c:833)
52  libR.dylib                    	       0x100b36af0 FORCE_PROMISE + 8 (eval.c:5467) [inlined]
53  libR.dylib                    	       0x100b36af0 getvar + 688 (eval.c:5508)
54  libR.dylib                    	       0x100b13578 bcEval + 15992 (eval.c:7198)
55  libR.dylib                    	       0x100b0f088 Rf_eval + 584 (eval.c:1013)
56  libR.dylib                    	       0x100b2bd0c R_execClosure + 3084
57  libR.dylib                    	       0x100b2a58c Rf_applyClosure + 524 (eval.c:2113)
58  libR.dylib                    	       0x100b16244 bcEval + 27460 (eval.c:7414)
59  libR.dylib                    	       0x100b0f088 Rf_eval + 584 (eval.c:1013)
60  libR.dylib                    	       0x100b29ca4 forcePromise + 164 (eval.c:833)
61  libR.dylib                    	       0x100b36af0 FORCE_PROMISE + 8 (eval.c:5467) [inlined]
62  libR.dylib                    	       0x100b36af0 getvar + 688 (eval.c:5508)
63  libR.dylib                    	       0x100b13578 bcEval + 15992 (eval.c:7198)
64  libR.dylib                    	       0x100b0f088 Rf_eval + 584 (eval.c:1013)
65  libR.dylib                    	       0x100b29ca4 forcePromise + 164 (eval.c:833)
66  libR.dylib                    	       0x100b36af0 FORCE_PROMISE + 8 (eval.c:5467) [inlined]
67  libR.dylib                    	       0x100b36af0 getvar + 688 (eval.c:5508)
68  libR.dylib                    	       0x100b13578 bcEval + 15992 (eval.c:7198)
69  libR.dylib                    	       0x100b0f088 Rf_eval + 584 (eval.c:1013)
70  libR.dylib                    	       0x100b29ca4 forcePromise + 164 (eval.c:833)
71  libR.dylib                    	       0x100b36af0 FORCE_PROMISE + 8 (eval.c:5467) [inlined]
72  libR.dylib                    	       0x100b36af0 getvar + 688 (eval.c:5508)
73  libR.dylib                    	       0x100b13578 bcEval + 15992 (eval.c:7198)
74  libR.dylib                    	       0x100b0f088 Rf_eval + 584 (eval.c:1013)
75  libR.dylib                    	       0x100b29ca4 forcePromise + 164 (eval.c:833)
76  libR.dylib                    	       0x100b36af0 FORCE_PROMISE + 8 (eval.c:5467) [inlined]
77  libR.dylib                    	       0x100b36af0 getvar + 688 (eval.c:5508)
78  libR.dylib                    	       0x100b13578 bcEval + 15992 (eval.c:7198)
79  libR.dylib                    	       0x100b0f088 Rf_eval + 584 (eval.c:1013)
80  libR.dylib                    	       0x100b29ca4 forcePromise + 164 (eval.c:833)
81  libR.dylib                    	       0x100b36af0 FORCE_PROMISE + 8 (eval.c:5467) [inlined]
82  libR.dylib                    	       0x100b36af0 getvar + 688 (eval.c:5508)
83  libR.dylib                    	       0x100b13578 bcEval + 15992 (eval.c:7198)
84  libR.dylib                    	       0x100b0f088 Rf_eval + 584 (eval.c:1013)
85  libR.dylib                    	       0x100b2bd0c R_execClosure + 3084
86  libR.dylib                    	       0x100b2a58c Rf_applyClosure + 524 (eval.c:2113)
87  libR.dylib                    	       0x100b16244 bcEval + 27460 (eval.c:7414)
88  libR.dylib                    	       0x100b0f088 Rf_eval + 584 (eval.c:1013)
89  libR.dylib                    	       0x100b2bd0c R_execClosure + 3084
90  libR.dylib                    	       0x100b2a58c Rf_applyClosure + 524 (eval.c:2113)
91  libR.dylib                    	       0x100b16244 bcEval + 27460 (eval.c:7414)
92  libR.dylib                    	       0x100b0f088 Rf_eval + 584 (eval.c:1013)
93  libR.dylib                    	       0x100b2bd0c R_execClosure + 3084
94  libR.dylib                    	       0x100b2a58c Rf_applyClosure + 524 (eval.c:2113)
95  libR.dylib                    	       0x100b16244 bcEval + 27460 (eval.c:7414)
96  libR.dylib                    	       0x100b0f088 Rf_eval + 584 (eval.c:1013)
97  libR.dylib                    	       0x100b29ca4 forcePromise + 164 (eval.c:833)
98  libR.dylib                    	       0x100b36af0 FORCE_PROMISE + 8 (eval.c:5467) [inlined]
99  libR.dylib                    	       0x100b36af0 getvar + 688 (eval.c:5508)
100 libR.dylib                    	       0x100b13578 bcEval + 15992 (eval.c:7198)
101 libR.dylib                    	       0x100b0f088 Rf_eval + 584 (eval.c:1013)
102 libR.dylib                    	       0x100b29ca4 forcePromise + 164 (eval.c:833)
103 libR.dylib                    	       0x100b36af0 FORCE_PROMISE + 8 (eval.c:5467) [inlined]
104 libR.dylib                    	       0x100b36af0 getvar + 688 (eval.c:5508)
105 libR.dylib                    	       0x100b13578 bcEval + 15992 (eval.c:7198)
106 libR.dylib                    	       0x100b0f088 Rf_eval + 584 (eval.c:1013)
107 libR.dylib                    	       0x100b2bd0c R_execClosure + 3084
108 libR.dylib                    	       0x100b2a58c Rf_applyClosure + 524 (eval.c:2113)
109 libR.dylib                    	       0x100b16244 bcEval + 27460 (eval.c:7414)
110 libR.dylib                    	       0x100b0f088 Rf_eval + 584 (eval.c:1013)
111 libR.dylib                    	       0x100b2bd0c R_execClosure + 3084
112 libR.dylib                    	       0x100b2a58c Rf_applyClosure + 524 (eval.c:2113)
113 libR.dylib                    	       0x100b16244 bcEval + 27460 (eval.c:7414)
114 libR.dylib                    	       0x100b0f088 Rf_eval + 584 (eval.c:1013)
115 libR.dylib                    	       0x100b2bd0c R_execClosure + 3084
116 libR.dylib                    	       0x100b2a58c Rf_applyClosure + 524 (eval.c:2113)
117 libR.dylib                    	       0x100b16244 bcEval + 27460 (eval.c:7414)
118 libR.dylib                    	       0x100b0f088 Rf_eval + 584 (eval.c:1013)
119 libR.dylib                    	       0x100b2bd0c R_execClosure + 3084
120 libR.dylib                    	       0x100b2a58c Rf_applyClosure + 524 (eval.c:2113)
121 libR.dylib                    	       0x100b16244 bcEval + 27460 (eval.c:7414)
122 libR.dylib                    	       0x100b0f088 Rf_eval + 584 (eval.c:1013)
123 libR.dylib                    	       0x100b2bd0c R_execClosure + 3084
124 libR.dylib                    	       0x100b2a58c Rf_applyClosure + 524 (eval.c:2113)
125 libR.dylib                    	       0x100b16244 bcEval + 27460 (eval.c:7414)
126 libR.dylib                    	       0x100b0f088 Rf_eval + 584 (eval.c:1013)
127 libR.dylib                    	       0x100b2bd0c R_execClosure + 3084
128 libR.dylib                    	       0x100b2a58c Rf_applyClosure + 524 (eval.c:2113)
129 libR.dylib                    	       0x100b16244 bcEval + 27460 (eval.c:7414)
130 libR.dylib                    	       0x100b0f088 Rf_eval + 584 (eval.c:1013)
131 libR.dylib                    	       0x100b2bd0c R_execClosure + 3084
132 libR.dylib                    	       0x100b2a58c Rf_applyClosure + 524 (eval.c:2113)
133 libR.dylib                    	       0x100b16244 bcEval + 27460 (eval.c:7414)
134 libR.dylib                    	       0x100b0f088 Rf_eval + 584 (eval.c:1013)
135 libR.dylib                    	       0x100b29ca4 forcePromise + 164 (eval.c:833)
136 libR.dylib                    	       0x100b36af0 FORCE_PROMISE + 8 (eval.c:5467) [inlined]
137 libR.dylib                    	       0x100b36af0 getvar + 688 (eval.c:5508)
138 libR.dylib                    	       0x100b13578 bcEval + 15992 (eval.c:7198)
139 libR.dylib                    	       0x100b0f088 Rf_eval + 584 (eval.c:1013)
140 libR.dylib                    	       0x100b29ca4 forcePromise + 164 (eval.c:833)
141 libR.dylib                    	       0x100b36af0 FORCE_PROMISE + 8 (eval.c:5467) [inlined]
142 libR.dylib                    	       0x100b36af0 getvar + 688 (eval.c:5508)
143 libR.dylib                    	       0x100b13578 bcEval + 15992 (eval.c:7198)
144 libR.dylib                    	       0x100b0f088 Rf_eval + 584 (eval.c:1013)
145 libR.dylib                    	       0x100b29ca4 forcePromise + 164 (eval.c:833)
146 libR.dylib                    	       0x100b36af0 FORCE_PROMISE + 8 (eval.c:5467) [inlined]
147 libR.dylib                    	       0x100b36af0 getvar + 688 (eval.c:5508)
148 libR.dylib                    	       0x100b13578 bcEval + 15992 (eval.c:7198)
149 libR.dylib                    	       0x100b0f088 Rf_eval + 584 (eval.c:1013)
150 libR.dylib                    	       0x100b29ca4 forcePromise + 164 (eval.c:833)
151 libR.dylib                    	       0x100b36af0 FORCE_PROMISE + 8 (eval.c:5467) [inlined]
152 libR.dylib                    	       0x100b36af0 getvar + 688 (eval.c:5508)
153 libR.dylib                    	       0x100b13578 bcEval + 15992 (eval.c:7198)
154 libR.dylib                    	       0x100b0f088 Rf_eval + 584 (eval.c:1013)
155 libR.dylib                    	       0x100b29ca4 forcePromise + 164 (eval.c:833)
156 libR.dylib                    	       0x100b36af0 FORCE_PROMISE + 8 (eval.c:5467) [inlined]
157 libR.dylib                    	       0x100b36af0 getvar + 688 (eval.c:5508)
158 libR.dylib                    	       0x100b13578 bcEval + 15992 (eval.c:7198)
159 libR.dylib                    	       0x100b0f088 Rf_eval + 584 (eval.c:1013)
160 libR.dylib                    	       0x100b2bd0c R_execClosure + 3084
161 libR.dylib                    	       0x100b2a58c Rf_applyClosure + 524 (eval.c:2113)
162 libR.dylib                    	       0x100b16244 bcEval + 27460 (eval.c:7414)
163 libR.dylib                    	       0x100b0f088 Rf_eval + 584 (eval.c:1013)
164 libR.dylib                    	       0x100b2bd0c R_execClosure + 3084
165 libR.dylib                    	       0x100b2a58c Rf_applyClosure + 524 (eval.c:2113)
166 libR.dylib                    	       0x100b16244 bcEval + 27460 (eval.c:7414)
167 libR.dylib                    	       0x100b0f088 Rf_eval + 584 (eval.c:1013)
168 libR.dylib                    	       0x100b2bd0c R_execClosure + 3084
169 libR.dylib                    	       0x100b2a58c Rf_applyClosure + 524 (eval.c:2113)
170 libR.dylib                    	       0x100b16244 bcEval + 27460 (eval.c:7414)
171 libR.dylib                    	       0x100b0f088 Rf_eval + 584 (eval.c:1013)
172 libR.dylib                    	       0x100b2bd0c R_execClosure + 3084
173 libR.dylib                    	       0x100b2a58c Rf_applyClosure + 524 (eval.c:2113)
174 libR.dylib                    	       0x100b16244 bcEval + 27460 (eval.c:7414)
175 libR.dylib                    	       0x100b0f088 Rf_eval + 584 (eval.c:1013)
176 libR.dylib                    	       0x100b2bd0c R_execClosure + 3084
177 libR.dylib                    	       0x100b2a58c Rf_applyClosure + 524 (eval.c:2113)
178 libR.dylib                    	       0x100b16244 bcEval + 27460 (eval.c:7414)
179 libR.dylib                    	       0x100b0f088 Rf_eval + 584 (eval.c:1013)
180 libR.dylib                    	       0x100b2bd0c R_execClosure + 3084
181 libR.dylib                    	       0x100b2a58c Rf_applyClosure + 524 (eval.c:2113)
182 libR.dylib                    	       0x100b0f35c Rf_eval + 1308 (eval.c:1140)
183 libR.dylib                    	       0x100b2bd0c R_execClosure + 3084
184 libR.dylib                    	       0x100b2a58c Rf_applyClosure + 524 (eval.c:2113)
185 libR.dylib                    	       0x100b0f35c Rf_eval + 1308 (eval.c:1140)
186 libR.dylib                    	       0x100aae644 do_docall + 644 (coerce.c:2746)
187 libR.dylib                    	       0x100b16a64 bcEval + 29540 (eval.c:7446)
188 libR.dylib                    	       0x100b0f088 Rf_eval + 584 (eval.c:1013)
189 libR.dylib                    	       0x100b2bd0c R_execClosure + 3084
190 libR.dylib                    	       0x100b2a58c Rf_applyClosure + 524 (eval.c:2113)
191 libR.dylib                    	       0x100b0f35c Rf_eval + 1308 (eval.c:1140)
192 libR.dylib                    	       0x100aae644 do_docall + 644 (coerce.c:2746)
193 libR.dylib                    	       0x100b16a64 bcEval + 29540 (eval.c:7446)
194 libR.dylib                    	       0x100b0f088 Rf_eval + 584 (eval.c:1013)
195 libR.dylib                    	       0x100b2bd0c R_execClosure + 3084
196 libR.dylib                    	       0x100b2a58c Rf_applyClosure + 524 (eval.c:2113)
197 libR.dylib                    	       0x100b0f35c Rf_eval + 1308 (eval.c:1140)
198 libR.dylib                    	       0x100b29ca4 forcePromise + 164 (eval.c:833)
199 libR.dylib                    	       0x100b36af0 FORCE_PROMISE + 8 (eval.c:5467) [inlined]
200 libR.dylib                    	       0x100b36af0 getvar + 688 (eval.c:5508)
201 libR.dylib                    	       0x100b13578 bcEval + 15992 (eval.c:7198)
202 libR.dylib                    	       0x100b0f088 Rf_eval + 584 (eval.c:1013)
203 libR.dylib                    	       0x100b2bd0c R_execClosure + 3084
204 libR.dylib                    	       0x100b2a58c Rf_applyClosure + 524 (eval.c:2113)
205 libR.dylib                    	       0x100b0f35c Rf_eval + 1308 (eval.c:1140)
206 libR.dylib                    	       0x100b2e48c do_begin + 396 (eval.c:2798)
207 libR.dylib                    	       0x100b0f288 Rf_eval + 1096 (eval.c:1092)
208 libR.dylib                    	       0x100b29ca4 forcePromise + 164 (eval.c:833)
209 libR.dylib                    	       0x100b36af0 FORCE_PROMISE + 8 (eval.c:5467) [inlined]
210 libR.dylib                    	       0x100b36af0 getvar + 688 (eval.c:5508)
211 libR.dylib                    	       0x100b13578 bcEval + 15992 (eval.c:7198)
212 libR.dylib                    	       0x100b0f088 Rf_eval + 584 (eval.c:1013)
213 libR.dylib                    	       0x100b2bd0c R_execClosure + 3084
214 libR.dylib                    	       0x100b2a58c Rf_applyClosure + 524 (eval.c:2113)
215 libR.dylib                    	       0x100b0f35c Rf_eval + 1308 (eval.c:1140)
216 libR.dylib                    	       0x100b29ca4 forcePromise + 164 (eval.c:833)
217 libR.dylib                    	       0x100b36af0 FORCE_PROMISE + 8 (eval.c:5467) [inlined]
218 libR.dylib                    	       0x100b36af0 getvar + 688 (eval.c:5508)
219 libR.dylib                    	       0x100b13578 bcEval + 15992 (eval.c:7198)
220 libR.dylib                    	       0x100b0f088 Rf_eval + 584 (eval.c:1013)
221 libR.dylib                    	       0x100b29ca4 forcePromise + 164 (eval.c:833)
222 libR.dylib                    	       0x100b36af0 FORCE_PROMISE + 8 (eval.c:5467) [inlined]
223 libR.dylib                    	       0x100b36af0 getvar + 688 (eval.c:5508)
224 libR.dylib                    	       0x100b13578 bcEval + 15992 (eval.c:7198)
225 libR.dylib                    	       0x100b0f088 Rf_eval + 584 (eval.c:1013)
226 libR.dylib                    	       0x100b29ca4 forcePromise + 164 (eval.c:833)
227 libR.dylib                    	       0x100b36af0 FORCE_PROMISE + 8 (eval.c:5467) [inlined]
228 libR.dylib                    	       0x100b36af0 getvar + 688 (eval.c:5508)
229 libR.dylib                    	       0x100b13578 bcEval + 15992 (eval.c:7198)
230 libR.dylib                    	       0x100b0f088 Rf_eval + 584 (eval.c:1013)
231 libR.dylib                    	       0x100b29ca4 forcePromise + 164 (eval.c:833)
232 libR.dylib                    	       0x100b36af0 FORCE_PROMISE + 8 (eval.c:5467) [inlined]
233 libR.dylib                    	       0x100b36af0 getvar + 688 (eval.c:5508)
234 libR.dylib                    	       0x100b13578 bcEval + 15992 (eval.c:7198)
235 libR.dylib                    	       0x100b0f088 Rf_eval + 584 (eval.c:1013)
236 libR.dylib                    	       0x100b29ca4 forcePromise + 164 (eval.c:833)
237 libR.dylib                    	       0x100b36af0 FORCE_PROMISE + 8 (eval.c:5467) [inlined]
238 libR.dylib                    	       0x100b36af0 getvar + 688 (eval.c:5508)
239 libR.dylib                    	       0x100b13578 bcEval + 15992 (eval.c:7198)
240 libR.dylib                    	       0x100b0f088 Rf_eval + 584 (eval.c:1013)
241 libR.dylib                    	       0x100b2bd0c R_execClosure + 3084
242 libR.dylib                    	       0x100b2a58c Rf_applyClosure + 524 (eval.c:2113)
243 libR.dylib                    	       0x100b16244 bcEval + 27460 (eval.c:7414)
244 libR.dylib                    	       0x100b0f088 Rf_eval + 584 (eval.c:1013)
245 libR.dylib                    	       0x100b2bd0c R_execClosure + 3084
246 libR.dylib                    	       0x100b2a58c Rf_applyClosure + 524 (eval.c:2113)
247 libR.dylib                    	       0x100b16244 bcEval + 27460 (eval.c:7414)
248 libR.dylib                    	       0x100b0f088 Rf_eval + 584 (eval.c:1013)
249 libR.dylib                    	       0x100b2bd0c R_execClosure + 3084
250 libR.dylib                    	       0x100b2a58c Rf_applyClosure + 524 (eval.c:2113)
251 libR.dylib                    	       0x100b16244 bcEval + 27460 (eval.c:7414)
252 libR.dylib                    	       0x100b0f088 Rf_eval + 584 (eval.c:1013)
253 libR.dylib                    	       0x100b29ca4 forcePromise + 164 (eval.c:833)
254 libR.dylib                    	       0x100b36af0 FORCE_PROMISE + 8 (eval.c:5467) [inlined]
255 libR.dylib                    	       0x100b36af0 getvar + 688 (eval.c:5508)
256 libR.dylib                    	       0x100b13578 bcEval + 15992 (eval.c:7198)
257 libR.dylib                    	       0x100b0f088 Rf_eval + 584 (eval.c:1013)
258 libR.dylib                    	       0x100b29ca4 forcePromise + 164 (eval.c:833)
259 libR.dylib                    	       0x100b36af0 FORCE_PROMISE + 8 (eval.c:5467) [inlined]
260 libR.dylib                    	       0x100b36af0 getvar + 688 (eval.c:5508)
261 libR.dylib                    	       0x100b13578 bcEval + 15992 (eval.c:7198)
262 libR.dylib                    	       0x100b0f088 Rf_eval + 584 (eval.c:1013)
263 libR.dylib                    	       0x100b2bd0c R_execClosure + 3084
264 libR.dylib                    	       0x100b2a58c Rf_applyClosure + 524 (eval.c:2113)
265 libR.dylib                    	       0x100b16244 bcEval + 27460 (eval.c:7414)
266 libR.dylib                    	       0x100b0f088 Rf_eval + 584 (eval.c:1013)
267 libR.dylib                    	       0x100b2bd0c R_execClosure + 3084
268 libR.dylib                    	       0x100b2a58c Rf_applyClosure + 524 (eval.c:2113)
269 libR.dylib                    	       0x100b16244 bcEval + 27460 (eval.c:7414)
270 libR.dylib                    	       0x100b0f088 Rf_eval + 584 (eval.c:1013)
271 libR.dylib                    	       0x100b2bd0c R_execClosure + 3084
272 libR.dylib                    	       0x100b2a58c Rf_applyClosure + 524 (eval.c:2113)
273 libR.dylib                    	       0x100b16244 bcEval + 27460 (eval.c:7414)
274 libR.dylib                    	       0x100b0f088 Rf_eval + 584 (eval.c:1013)
275 libR.dylib                    	       0x100b2bd0c R_execClosure + 3084
276 libR.dylib                    	       0x100b2a58c Rf_applyClosure + 524 (eval.c:2113)
277 libR.dylib                    	       0x100b0f35c Rf_eval + 1308 (eval.c:1140)
278 libR.dylib                    	       0x100b2e48c do_begin + 396 (eval.c:2798)
279 libR.dylib                    	       0x100b0f288 Rf_eval + 1096 (eval.c:1092)
280 libR.dylib                    	       0x100b633f4 Rf_ReplIteration + 756 (main.c:262)
281 libR.dylib                    	       0x100b64968 R_ReplConsole + 168 (main.c:314)
282 libR.dylib                    	       0x100b648a4 run_Rmainloop + 100 (main.c:1200)
283 libR.dylib                    	       0x100b64a10 Rf_mainloop + 16 (main.c:1207)
284 R                             	       0x10062bea0 main + 32
285 dyld                          	       0x185e7ff28 start + 2236

[gaborcsardi]

Thanks! Is this the test process or a subprocess of the test process?

[kevinushey]

Other traces look different, but one common thing I'm noticing is that R is being run on multiple threads...

Thread 0 Crashed::  Dispatch queue: com.apple.main-thread
0   libR.dylib                    	       0x104ddde18 Rf_framedepth + 32 (context.c:447) [inlined]
1   libR.dylib                    	       0x104ddde18 do_sys + 280 (context.c:666)
2   libR.dylib                    	       0x104e2aa64 bcEval + 29540 (eval.c:7446)
3   libR.dylib                    	       0x104e23088 Rf_eval + 584 (eval.c:1013)
4   libR.dylib                    	       0x104e3fd0c R_execClosure + 3084
5   libR.dylib                    	       0x104e3e58c Rf_applyClosure + 524 (eval.c:2113)
6   libR.dylib                    	       0x104e2a244 bcEval + 27460 (eval.c:7414)
7   libR.dylib                    	       0x104e23088 Rf_eval + 584 (eval.c:1013)
8   libR.dylib                    	       0x104e3dca4 forcePromise + 164 (eval.c:833)
9   libR.dylib                    	       0x104e4aaf0 FORCE_PROMISE + 8 (eval.c:5467) [inlined]
10  libR.dylib                    	       0x104e4aaf0 getvar + 688 (eval.c:5508)
11  libR.dylib                    	       0x104e27578 bcEval + 15992 (eval.c:7198)
12  libR.dylib                    	       0x104e23088 Rf_eval + 584 (eval.c:1013)
13  libR.dylib                    	       0x104e3fd0c R_execClosure + 3084
14  libR.dylib                    	       0x104e3e58c Rf_applyClosure + 524 (eval.c:2113)
15  libR.dylib                    	       0x104e2a244 bcEval + 27460 (eval.c:7414)

Thread 1:
0   libR.dylib                    	       0x104e1e57c R_GetTracebackOnly + 60 (errors.c:1566)
1   libR.dylib                    	       0x104e1e724 R_GetTraceback + 36 (errors.c:1607)
2   libR.dylib                    	       0x104e79f60 sigactionSegv + 352 (main.c:602)
3   libsystem_platform.dylib      	       0x186206a24 _sigtramp + 56

It seems like the SEGV handler isn't actually being run on the main R thread? So the processx bit might be a red herring; it's more that we have multiple threads and the signal handler isn't being assigned to the main thread for some reason?

[jennybc]

I'm just here to say that I experienced something that presented exactly like this:

At least on macOS, those processes get stuck in an infinite busy loop, chewing up lots of CPU

while running testthat's tests (by mistake), then interrupting them.

[gaborcsardi]

This is now fixed in processx with r-lib/processx@da4cf5a

I'll make a processx release sure, after which testthat could depend on the new processx version. Until then, you can use the R_NO_SEGV_HANDLER workaround.