If you look past all those backslashes, the post build hook is adding the command OUT_PATHS=$OUT_PATHS /run/uploadToCache to the queue (where $OUT_PATHS has been substituted for the actual value). This only works when $OUT_PATHS contains no spaces.
As an example, running pueue add -- VAR="hello world" printenv VAR adds the command VAR=hello world printenv VAR to the queue, which is not what we want. The queue tries to run a command called world with arguments printenv and VAR. The problem is that the quotes around the variable aren't carried onto the queue. We need to run pueue add -- VAR=\"hello world\" printenv VAR so that the queue executes VAR="hello world" printenv VAR.
If you look past all those backslashes, the post build hook is adding the command
OUT_PATHS=$OUT_PATHS /run/uploadToCacheto the queue (where$OUT_PATHShas been substituted for the actual value). This only works when$OUT_PATHScontains no spaces.As an example, running
pueue add -- VAR="hello world" printenv VARadds the commandVAR=hello world printenv VARto the queue, which is not what we want. The queue tries to run a command calledworldwith argumentsprintenvandVAR. The problem is that the quotes around the variable aren't carried onto the queue. We need to runpueue add -- VAR=\"hello world\" printenv VARso that the queue executesVAR="hello world" printenv VAR.