prevent logs being read and written to at the same time #82
Description
From a CI job:
logs/iroh__2_to_4__i_srv_0_r1.txt
logs/iroh__1_to_10__i_get_6_r3.txt
logs/iroh__1_to_3__i_get_0_r1.txt
logs/iroh__2_to_2__i_srv_0_r0.txt
logs/iroh__2_to_10__i_srv_0_r3.txt
tar: logs/iroh__2_to_10__i_srv_0_r3.txt: file changed as we read it
logs/iroh__1_to_5__i_get_4_r2.txt
logs/iroh__2_to_6__i_get_3_r2.txt
logs/iroh__2_to_4__i_get_3_r1.txt
logs/iroh__2_to_10__i_get_4_r3.txt
logs/iroh__2_to_10__i_get_7_r3.txt
report/
report/iroh__2_to_4__i_get.json
report/iroh__1_to_5__i_get.json
report/iroh__1_to_3__i_get.json
report/iroh__1_to_10__i_get.json
report/iroh__2_to_6__i_get.json
report/iroh__1_to_1__i_get.json
report/iroh__2_to_2__i_get.json
viz/