Fix no-argument ./build.sh invocation

[jkoritzinsky]

Fixes issue reported in #116145 (comment)

[Copilot]

Pull Request Overview

This PR ensures that running ./build.sh without any arguments no longer fails by initializing the arguments array with an empty element.

• Changed default arguments initialization to include an empty string.
• Preserves existing behavior of passing flags via the arguments array.

Comments suppressed due to low confidence (1)

eng/build.sh:156

• Using an empty string in the arguments array can lead to a spurious empty-argument being passed downstream. Consider explicitly detecting when no arguments are provided and handling that case, rather than injecting an empty element into the array.

arguments=("")

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[akoeplinger]

/ba-g fast merge as this is apparently not covered by CI otherwise we'd have seen it in #116145 and I verified it works locally.

[akoeplinger]

@omajid do we need to make similar changes for the other cases like this you added in dotnet/dotnet#677 and dotnet/dotnet#797 ?

[omajid]

@jkoritzinsky I think this fix is not quite right. This adds a single empty argument. That might break something.

@akoeplinger I thought I had fixed it via https://github.com/dotnet/dotnet/pull/797/files#diff-56c552fdb744de6c93ad3afef9db9a34839f7b4b0e0d3f653b41310dd62776a3. Is there something I need to do to help the fix flow in here?

[omajid]

Ah, I see. I think we need to guard this as well:

runtime/eng/build.sh

Line 590 in f03b2ab

for argument in "${arguments[@]}"; do

[akoeplinger]

@omajid it was actually complaining about

runtime/eng/build.sh

Line 552 in f03b2ab

arguments=("-restore" "-build" "${arguments[@]}")

[akoeplinger]

The for loop on L590 seems to work fine as is from what I can see

[omajid]

Thanks for finding and fixing it!