Last time I have seen this issue it was a result of some missing deps after work on the v8_context_snapshot. Could this be related?

I took a look corresponding build. commit a3a2f839787d4f4036568a3471fa4628bfffaec5

https://ci.chromium.org/p/v8/builders/luci.v8.ci/Linux%20Debug%20Builder/7810

And there seems to be a step generating snapshot.
[445/713] ACTION //v8:run_mksnapshot_default(//build/toolchain/linux:clang_x64)

So I'm skeptical that this is come from incorrect build dependency around snapshot.

Oh, but that might exactly be the problem. The snapshot got renewed, but the executables did not, e.g. look at the executables that fail, e.g.:
site_per_process_components_browsertests
network_service_content_browsertests
components_browsertests
etc

They are all not rebuild though they seem to depend on V8 and hence the newer snapshot. What I'm not getting is that since this is debug, it should be component build. And the V8 component should be there only once. Unless some of these tests are not component builds. E.g. in the isolated inputs https://isolateserver.appspot.com/browse?namespace=default-gzip&hash=ef99238dd4fefdb525c743e2184662d9eaf7c2db I can see that e.g. components_browsertests is quite large, and hence probably embeds V8.

#3, 
Hmm, yeah this is debug and component build. 
https://logs.chromium.org/logs/v8/buildbucket/cr-buildbucket.appspot.com/8940628803802154736/+/steps/generate_build_files/0/stdout

But components_browsertests is linked to v8 dynamically in component debug build.
tikuta@tikuta:~/chromium/src$ ldd out/Debug/components_browsertests | fgrep v8
        libv8.so => /usr/local/google/home/tikuta/chromium/src/out/Debug/./libv8.so (0x00007f18cb079000)
        libnet_with_v8.so => /usr/local/google/home/tikuta/chromium/src/out/Debug/./libnet_with_v8.so (0x00007f18c6c14000)
        libv8_libbase.so => /usr/local/google/home/tikuta/chromium/src/out/Debug/./libv8_libbase.so (0x00007f18bc095000)

So I think re-linking is not neccessary.

The bot turned green again...  but that doesn't mean that the bug is gone. It just might have built the right things again due to other code changes.